I think it's pretty clear now that the initial point about the 'plotholes' is cleared up now. I find the idea of betraying your own species much more interesting
"The humans returned to their dying world" is something Jake says towards the end of the film. Considering this and the lengths the humans go to to obtain unobtainium [http://en.wikipedia.org/wiki/Unobtainium] (which by the way is any substance that is perfect for the job but is unfeasibly hard to get), they
really need this stuff. Their planet is dying and unobtainium is their last shot at survival. But isn't their impending doom due to their lifestyle? They destroy and they consume, you can see that when they march towards Hometree. They are completely out of touch with their surroundings.
The Na'vi on the other hand live perfectly harmoniously with their environment, just look at how pissed Neytiri is when she saves Jake by killing the things coming after him. Jake's ignorant, "child-like",
human behaviour causes the unnecessary deaths of living things. The Na'vi are an example to the Humans. They need to find their place in their world like the Na'vi have. Even if they had beaten the Na'vi and had access to all the unobtainium they wanted, it would have run out eventually and then what? Find another world?
This is blatantly pointing at us modern day humans. How long have we been told by the scientists to live in a more sustainable way? How often do you hear about the more harmonious tribal humans causing environmental problems? How often do those tribal people get in the way of the corporations seeking their 'unobtainium'?
If you could choose between the resource-hungry, self-destructive humans and the harmonious, sustainable Na'vi, would you really stay human? Out of pure zealous patriotism?
For those of you who have endured to the end, I congratulate you and wish you a merry christmas
