If someone wants to hate a movie or find fault in a movie over something like say "originality", then by all means go for it. But there are a lot of more blatant rip offs and generic storylines out there than Avatar, that's for sure.
But to sit there and write up a full page essay about how this little bit represents racism, or stereotyping, or religious undertones, or oppression with the intent to do it is just the same kinda stuff that I would expect the "movie experts" at somethingawful's forum movie section to debate on and run into the ground. I guess everyone seems to have a sense of entitlement as to what a person should view as their views, but in the last few years it seems more and more in your face with the nitpickery and it really needs to be toned down. I'm sure Cameron isn't in league with "white man" to somehow oppress the native americans more in movie theaters and demoralize our children's vision.