I also like many things that the masses like. For instance, Star Wars 4-6, made a great use of human archetypes. The scenario was very well conceived, and there were a real team of competent designers behind this movie, people with taste -even if SW is not scientifically accurate-.
I also have to confess I liked Star Trek (the original serie), including the latest movie. Once again, what is really interesting are the characters and their interaction, something Avatar severely lacks.
Avatar also lacks humor, it is totally humorless. There's not even a single joke within it. And this is perhaps the greatest flaw of all, because it makes this movie looks even more ridiculous. And James Cameron genuinely thinks it is serious.
This is paradoxically why it is so laughable, why it looks so pretentious, and why I see no way to redeem it.
And about the scenario: