Audience's approval vs. skill of the craft

I'd say probably not. In fact, according to this interview I'd say he sees them as two sides to the same coin:

"I've also met enough magicians now to know there's a certain amount of truth to the way we've portrayed the rivalries and conflicts that can happen between them. Obviously, we've exaggerated it hugely for dramatic effect, but at the core of what a magician does, there is this massive, almost obsessive secrecy, and a lot of insecurity. They're people whose fame and fortune, by definition, is all based on the methods behind these tricks, most of which are pretty trivial and if you knew how they were done, you'd be very disappointed. They've built their entire lives around these methods, and all these untruths and insecurities mean there's a very extreme approach to their work."

Source: Christopher Nolan on The Prestige