"Avatar fails in one rather important respect. By common consent, its story's rubbish. James Cameron seems to have lifted Avatar's story from the movie-maker's trashcan... The film is mere spectacle, about as emotionally engaging as the associated videogame. Certainly, thinking like this seems pretty pervasive in Hollywood. In 2009, films such as Transformers: Revenge of the Fallen, Terminator Salvation and Fast & Furious have all seemed to reflect the assumption that emotional interaction is dispensable. Of course, movies like these do well at the box office, and so will Avatar." — David Cox, The Guardian
There are two arguments here, each contradicting one another: 1) Avatar's story is rubbish, and 2) Avatar's story is non-existent. People use "story" to mean all sorts of things, of course — "I didn't like the story" can turn out to mean everything from plot to mood. I suspect that what Cox means to fault is not that the narrative, which felt solid to me, but the dialogue, which contains a succession of howlers, as is always the case with Cameron, whose movies are like Vegas mansions: strong construction, lousy interior decoration. He may, in fact, have the worst taste of any working director. But the proportion of care taken over the story in Avatar compared to that taken in Transformers or Terminator: Salvation is approximately a 1000 to one. Cameron's narrative instincts are deep and unfakeable, such that they render the inadequacies of his scriptwriting largely moot: he tells the story with his camera, as does every great director from Griffith to Lynch.
The New Yorker's Richard Brody writes:—
The experience was surely exciting, and inspired, as Manohla Dargis says in the Times, “awe” (though not shock). What it didn’t engender was joy—the near-laughter at visual inventions that are so extravagant as to seem borderline ridiculous and that, at the same time, actually pack a new idea.Brody is fast turning into the 'Time Out' of film writers*: the guy whose opinions I can safely invert to get something close to my own reaction. It's very helpful. What he describes is exactly the reaction I did have. I felt myself close to laughter for much of the movie — the laughter born of pure flabberghast, like the delighted gurgling of a child. Critical reaction to the movie can be divided into two camps: those who have felt this and those who have not. If you have, you'll forgive the film anything and if you have not, well, there's always the theatre.
* I mean the London Time Out, not the New York one.