Why didn't Jesse shoot Walt?

I don't think he didn't shoot him because he forgave him.

I think the main reason he didn't shoot him was because he has finally escaped Walts control. Throughout the majority of the show Walt had Jesse under his control. Walt manipulated Jesse in many situations in order to benefit himself. An example was when he poisoned Brock to turn Jesse against Gus.

Jesse knew Walt had control over him and manipulated him and it hurt him as I believe Jesse cared for Walt and viewed him as a father figure. This was shown in the epiose "Confessions" where Walt met Jesse and Saul in the dessert when he wants to talk Jesse into leaving town. Jesse breaks down accusing Walt of not caring for him and only wants hime to leave town in order to hinder Hanks investigation instead of benefiting Jesse.

When it comes to the scene where Jesse has the oppurtunity to kill Walt, Walt hands him the gun and asks him to shoot him. I believe Jesse really considerates it as he must hbe harboring hatred toward him. But I think he doesn't shoot him because he wants to break free from Walts control. He does as he leaves without shooting him.

The important explaining moment is when Jesse noticed Walt was shot by the machine gun. If we look at Jesse in a normal situation - he is more of an ordinary man, definitely not a killer. He can murder on impulse or emotion but not on some purpose. His guilt always stops him from moving forward - he can fail his business or risk his life because of a child. Once he notices Walt's bleeding - a man dying of cancer who have just risked his life for him covering him from bullets, he calms down, becomes himself, his hatred is gone and he doesn't give a damn about Walt. He does not forgive him, I think he forgets him.

PS sorry, not a native speaker.

I thought of multiple possible reasons for this:

• Jesse forgave Walt. This is probably the most obvious one. He realizes that Walt did care for Jesse after all, even though Jesse was may a time an unwilling part of Walt's plan.
• Jesse thinks that Walt isn't worth it. Jesse was never fond of killing, and seems to want as less of it as possible. He doesn't want to kill Walt, even if Walt is asking for it as he doesn't like blood on his hands.
• Jesse is tired of doing what Walt asks him to. As @Travis said, he wants to break free of Walt's control.

However, the following reason is the one I like the most:

Jesse realizes that Walt is manipulating him, again. Jesse is angry at Walt, and about to shoot. Suddenly, he realizes that Walt is bleeding, and his facial expression changes. He decides not to shoot after all. Why? Maybe because he thinks that Walt knows that he is dying anyway, and this request to shoot is just his way of manipulating Jesse into feeling like he got his revenge. Jesse didn't like that, and decided not to oblige Walt and walk away.

Jesse's tragic flaw is his passion. When he's angry/upset/undermined, he lashes out without thinking and generally makes his life quite a lot more difficult for himself.

When Jesse has a chance to kill Walt, he has a chance to act on impulse, to get revenge, to prove that he outlasted and outsmarted Walt in the end. He has a chance to kill the man who poisoned a young boy and who watched his girlfriend die in her sleep. If the roles and story lines were reversed minus the character traits, Walt would kill Jesse in a heartbeat. But, Jesse isn't Walt, and that's what he proves in deciding not to kill Walt. He faces so much pressure throughout the show to be more like Walt, but Jesse proves himself to be far stronger than Walt ever is by ultimately not giving in to impulse and emotion.

Jesse's choice to let Walt die on his own is his way of saying 'I'm not you, nor will I ever be'. That's the real battle these two characters have been fighting since they teamed up, and Jesse ultimately wins it by not shooting Walt.

The important clue is in the exchange of glances between Walt and Jesse when they are outside afterwards, just before Jesse drives off. It's an exchange of glances that we often see at the end of movies where honours are finally even. That tells us that Jesse acknowledges that Walter came to the farm primarily to free him. (Walter threw himself on Jesse to save him from the machine gun fire and didn't wait to hear where his money was).

It's not that complicated:

Walt passes the gun to Jesse, who points it at him.

Walt: Do it. You want this.
Jesse: Say the words. Say you want this. Nothing happens until you say it.
Walt: I want this.
Jesse: Then do it yourself.

Clearly Jesse is not going to do what Walt wants. He's done being used by him. He's showing Walt that he has no more power over Jesse; he is free.

Jesse knew that if he shoots Walter, he will execute yet another bloody favor Walter prepared for him, meaning once again Jesse's abeyance admitting that Walter is still in control.

Because Jesse finally figured out that Walt uses people to get what he wants!

Do it yourself.

Walt came back for him. Not the money.