Has a TV showrunner ever blamed U.S. television content rating standards for compromising his/her creative vision?

This is a really interesting question.

I've tried to find some sort of list of "banned" television shows, but I came up completely empty. You are of course right that many directors and producers have complained about movies being damaged by content ratings, but not television shows. I did find some possible reasons why though.

To begin, it's worth reminding ourselves what the ratings actually are:

TVY: "All Children."

This program is designed to be appropriate for all children. Whether animated or live-action, the themes and elements in this program are specifically designed for a very young audience, including children from ages 2 - 6. This program is not expected to frighten younger children.

TVY7: "Directed to Older Children"

This program is designed for children age 7 and above.It may be more appropriate for children who have acquired the developmental skills needed to distinguish between make-believe and reality. Themes and elements in this program may include mild fantasy violence or comedic violence, or may frighten children under the age of 7. Therefore, parents may wish to consider the suitability of this program for their very young children. Note: For those programs where fantasy violence may be more intense or more combative than other programs in this category, such programs will be designated TV-Y7-FV.

TVG: "General Audiences"

Most parents would find this program suitable for all ages. Although this rating does not signify a program designed specifically for children, most parents may let younger children watch this program unattended. It contains little or no violence, no strong language and little or no sexual dialogue or situations.

TVPG: "Parental Guidance Suggested"

This program contains material that parents may find unsuitable for younger children. Many parents may want to watch it with their younger children. The theme itself may call for parental guidance and/or the program contains one or more of the following: moderate violence (V), some sexual situations (S), infrequent coarse language (L), or some suggestive dialogue (D).

TV14: "Parents Strongly Cautioned"

This program contains some material that many parents would find unsuitable for children under 14 years of age. Parents are strongly urged to exercise greater care in monitoring this program and are cautioned against letting children under the age of 14 watch unattended. This program contains one or more of the following: intense violence (V), intense sexual situations (S), strong coarse language (L), or intensely suggestive dialogue (D).

TVMA: "Mature Audiences Only"

This program is specifically designed to be viewed by adults and therefore may be unsuitable for children under 17. This program contains one or more of the following: graphic violence (V), explicit sexual activity (S), or crude indecent language (L).

Now, TV Guide actually did a report on these ratings, asking Does Anyone Care About TV's Content Ratings?. To quote some fascinating snippets from that article:

For most folks, the ratings bugs are just one more thing on an already cluttered TV screen. According to a 2007 study by the Kaiser Family Foundation, only 43 percent of respondents who had purchased a V-Chip-equipped [content restricting] TV since 2000 even knew of the technology, and just 16 percent of parents said they utilized it. The study also found that few viewers understood that "V" stands for "violence," "S" is "sex" and "D" means "suggestive dialogue." Even more comical, a percentage of parents polled thought "FV" — which warns of "fantasy violence" on kids' shows like Cartoon Network's Ben 10 — is an abbreviation for "family viewing." Oops.

So we can see that, unlike movie ratings which are fairly well known, TV content ratings aren't. There could be a few reasons for this, but I would argue the most likely is that movie ratings are extremely relevant for content released in the cinema or in stores as there are laws restricting what minors can purchase. Obviously many minors get their hands on these things anyway, but suffice to say restrictions are in place.

However, with TV Ratings it's much harder to restrict content. Whereas for movies the store is doing all the work in restricting content, for television the parent has to do the work. They need to set up the restriction software on the television and proactively use it. Many parents, who are perhaps not particularly technically savvy (thinking of my own mother here!) would struggle to do that. Without these restrictions, minors are free to watch pretty much whatever they want. Therefore, unlike with movies where a director may feel the change of rating has affected his overall "vision", with television series the creators may feel they are still hitting the "target audience" and therefore their vision hasn't been compromised.

Anyway, that is just a minor point and a theory to boot, but I thought I'd suggest. More importantly from that TV Guide article though is this:

Critics are mixed on how effective the system has been. Children Now national policy director Jeff McIntyre gives "50/50" marks to the ratings. "There are a lot of concerns about how the ratings are implemented and significant concerns about the consistency of the ratings," he says. "A show on CBS will have different ratings than a similar one on NBC, or shows in syndication have different ratings."

"The movie ratings system tends to get a little more press and social awareness, and tends to get integrated as a marketing mechanism," McIntyre says. But in comparison, TV content ratings rarely, if ever, get a rise out of producers or viewers. That's mostly because the TV networks rate themselves, via their internal standards and practices departments. Plus, in the movie world, a rating can impact box office, as many theater chains won't show unrated or NC-17 movies, and are strict about not letting kids into R-rated features.

"We could rate a show TV-MA [mature audiences only] and it's still going on the air, even if the affiliates don't like it," says a network exec. "There's no crossing guard in TV. If a 12-year-old watches a TV-MA show on TV, that's on the parents." There is an oversight board that serves as a clearinghouse for TV content ratings issues, but McIntyre says it's still difficult to figure out how to dispute ratings. "It's such a broad TV rating system, there's not a lot of clarity who you can go to if you have a complaint," he says.

So you can see that it is being argued that as networks are self rating, it's nowhere near as important for them to "fit" their show into a certain rating. If the show is too violent or sexual, they can simply label it suitable for Mature audiences and release it.

The article then continues, stating:

Critics had feared that the content ratings might give networks license to get dirtier, and McIntyre believes that early on, a handful of shows took advantage of the system to prove how "edgy" they were. The pilot to CBS' 1997 Steven Bochco drama Brooklyn South earned a bit of notoriety for being the first broadcast program to land a TV-MA, but that show didn't last long. Since then, Loesch says she doesn't think "there was any real purposeful effort to use ratings as a shield to get away with anything. There were a lot of naysayers and I think a lot of their predictions have never borne out to be true."

Loesch adds that even though she regularly hears from parents concerned over language and the sexualization of young girls in TV, that doesn't extend to the content ratings. "To tell you the truth I don't hear anything about the TV ratings," she says. "It's not a part of the conversation. The content itself is."

So again any "naysayers" appear to be complaining about what content is allowed to be shown, rather than the actual rating system. This suggests that producers/directors are quite at ease to create the show they want to create as they know a Mature rating can be given to it if necessary and the show will still be broadcast to a nationwide audience.

On a final note, I haven't found any shows that were so unsuitable that they weren't released. But this seems logical to me. Whilst I know there are banned movies, it seems difficult to imagine how a network could pay for a show that was so extreme it could never be released. If that happened, I would imagine the show's creators could be in legal difficulties. After all, for filming to go ahead the idea for the show, along with its content, would need to be agreed and verified. If they changed this to make it far more extreme/sexual/graphic/something, they would be validating that agreement. Not to mention the fact that the channel creating the show would be keeping track of it during production and would be able to "yank" it long before it go to air (e.g. if the pilot was unsuitable, nothing else would be commissioned).

I'm aware that article I've used primarily for this answer addresses the efficiency of content ratings as opposed to TV show-runners criticizing the ratings. But I hope it is still useful to you. It appears that directors/producers simply don't view the ratings system as much of an issue, compared to their counterparts in the movie business.

I think Andrew Martin's answer provides the main reason why this never happens: Shows usually get censored by the network, not by TV content rating standards. So showrunners will obviously blame the network if anyone.

This happens a lot, Family Guy for example, which often pushes the boundaries, regularly makes jokes within the episodes about their network Fox preventing them from showing certain content.

To add a more concrete example of censorship by the network, the episode I'll See You in Court of the classic TV show "Married with Children" with the plot revolving around a sex tape was not aired because of the controversial sexual content.

Conflict erupted between the show's producers and the airing network over the episode's content, which prevented the episode from being aired for well over a decade, far past Married... with Children's initial television run. Even when first shown on American television in 2002, four lines were removed from the broadcast, despite it having already run uncut in other countries.

"Married with Children" is a good example of the censor department of a network tampering with the creative vision of a show that was rather bold for the time:

The censors of the Fox Broadcasting Company, however, objected to many of the lines in the show. It was not the first time that Fox censors had struggled with the content in Married... with Children. Earlier in the season, producers and writers Michael G. Moye and Ron Leavitt had to fight with the censors to air "The Camping Show", an episode where the Bundys and the Rhodes are trapped in a cabin in the wilderness as all three women have their periods at the same time. It was originally intended to be shown in November 1988, but its airing was delayed while the network wrangled with the subject matter. The episode aired on December 11, 1988, but the producers were forced to change the title from "A Period Piece" to "The Camping Show", despite the fact that the title itself does not appear onscreen and is not mentioned during the program.

So why would the network have an interest in censoring its own shows?

There are mostly two reasons which come down to image and money:

• If the network shows content considered offensive and inadequate by the viewers, they will lose reputation and viewership.
• One of the main concerns of any network is advertisement. If content is deemed offensive by a large portion of viewers, the advertising companies will not want to run their clips during this show. This was also the main reason the episode mentioned above was not aired:

The censors ended up pulling "I'll See You in Court", preventing it from airing in the United States during the series' original run. Terry Rakolta, a woman from Bloomfield Hills, Michigan, had launched a letter-writing campaign against the program after viewing the Season 3 episode "Her Cups Runneth Over" in January 1989. Offended by the episode's content, she urged advertisers to boycott the show, several of whom did or pledged to more carefully screen the episodes for which they provided advertising. The campaign garnered more media attention than she had expected and the advertisers' more careful scrutiny of the individual episodes that they supported was a significant factor that led to the pulling of I'll See You in Court.

Obviously this is a situation any network wants to avoid badly, so they run rigorous censoring departments that review every episode before airing and dictate the show in advance what is and isn't allowed.