Quote Originally Posted by animus
But according to your logic, the ability to walk again in a body and race that is not your own to spend your life with an alien wife among aliens who you've only spent 3 months with is worth the price of killing off and waging war against your own very race just because Earth is barren and desolate.
I think you really misunderstood the decision Jake had to make. His choice was not "Go back to being a human with legs or remain with the Na'vi and wage war on humans." There was literally no point in the movie where he was capable of making that decision.

Quaritch promised Jake his operation, then proceeded to destroy the Na'vi Hometree, mudering handfuls and destroying their home and way of life. Then he launched an attack on the Tree of Souls, threatening their physical link with the planet and primary means of subsistence. This was largely due to Jake's previous inaction, but the events of the story still force Jake into a decision.

His choice was then "Turn a blind eye to injustice or defend the world he was now literally bonded to." An entire hour and a half of the movie is devoted to showing why Jake would choose the latter option. Defending against injustice is not "betraying your race" and I can think of no logical argument why Jake would have not defended the Na'vi, ex-marine or no. After that point, he had literally no reason to return to being a broken and unwanted human. And even if he had, he would have returned to an Earth where'd he'd face ramifications for his actions. After killing Quaritch (even in self defense), his option for surgery was no longer present. His decision to defend the Na'vi nullified his deal with Quaritch.

He didn't "betray his race" in the same way a white girl from a conservative family doesn't betray their race by marrying a black man. He made a decision and lived with the consequences. It just so happens his decision was a moral one, at least from the narrative's perspective.

Now, you can argue about the implicit arguments in those consequences. The film intentionally blurs the line between "dreaming" and "reality" and does so from the get go. By the end of the movie it seems to be showing the idea of leaving behind a feeble body in favor of a perfect escapist reality in a favorable light. You can argue about the subtext all you wish, but Jake's motives are pretty explicitly justified in terms of the plot. There's absolutely no questioning why he would stay.

Your argument about Jake falling in love "too easily" is ridiculous and really not worth getting into.