By the end of the film you're left wondering why the film needed the Jake Sully character at all. The film could have done just as well by focusing on an actual Na'vi native who comes into contact with crazy humans who have no respect for the environment.
This would be true of any film dealing with a real
race. When these comparisons come up, I love to observe (pointlessly, no doubt) that the original idea for Battle of Algiers is that it was going to be about a French paratrooper, played by Paul Newman, who becomes disillusioned with the French occupation and switches sides. Thankfully that didn't come to pass.
The Na'vi, however, have two problems. The first is that being an alien fictive culture they are inherently less relatable than a human character (though the human character of course need not be white, even if he almost always is). We are the outsiders, and we need this culture and its logic explained to us - through a similarly ignorant main character is as good a way as anyway.
The second problem is that they're CGI. The plot device of a real actor slipping into a CGI performance is a way to gently lead us into a film where the protagonist spends whole stretches of the film as a CGI creation.
Anyway, an interesting read. I'd agree that District 9 had a more interesting spin on these tropes than Avatar did, also. Also, can I use this thread to vent once more my long enduring hatred for The Last King of Scotland? Because everything about the McAvoy character in that film is terrible.