I've been trying to figure it out and I think that, innately, most of us are cranky for a good reason with the bad reviews and others who feel they need to tell us how 'crap' Avatar was.
Obviously, from reading this wiki constantly the last few days, I can see that most all of us 'got the message' watching this film.
And what a brilliant message. Nothing ever seemed so pure or right as the feeling I got watching this. I guarantee when most of us (you know who you are) left the film, we became very introspective of our lives. Suddenly the daily grind didn't seem to matter, NOTHING really mattered, because we suddenly understood that even though Pandora might not be real, there was something bigger than us. Something that mattered more than our petty everyday problems. Suddenly I'm buying fresh fruit and veg. Every time I see printed packaging competing with another printed package of the same damn stuff it makes me sad. Hell, I was driving the other day and saw the local council chopping down a big beautiful tree because it was 'inconvenient' and found myself ANGRY.
I never cared before. But I see these things and think "How the hell can I change it. I'm just one person". I might change the way I eat, plant some trees. But I still have to drive to get to work. If I want milk I still have to buy it in a plastic bottle (albeit a recyclable one).
Truth is as a society we're so entrenched in our ways of convenience, making money, and expanding our own little space trying in vain to feel significant and important in a vast universe that we could never hope to make a mark on, that we forget the things we CAN do. Not only to make our own lives richer and more fulfilling, but to preserve what was given to us in the first place.
Point is WE got the message. We realize something greater that could be accomplished, and when people chose to ignore this, or crap on it, it makes us feel all the more helpless about an already staggering task.
Trying to make themselves stand out, ignoring the truth that we're all in this together. That's what makes me feel angry and disappointed in these people.