I think the OP has some very high standards of film, which anything popular from Hollywood really would not match up to. Really, we have to keep in mind that Avatar is a Hollywood-style action film. The genre has never been known for story strength, instead it's been known for heroics and escapism, and both of these qualities the movie does very well. Critically analysing the film like you would an indy or arthouse flick just removes it far away from its actual purpose in being made.