Here's the operating analogy: the people who viewed AVATAR and had this reaction to it are comparable to people who ate a certain food for the first time without knowing that they are allergic to it. It's a rare and unusual allergy, and the people who consumed the food had no idea that they had such an allergy. Now that they've had an allergic reaction, they go to the doctor to find out what's wrong and get cured.
We wouldn't call such people idiots, would we?
Now if those same people knew of such an allergic reaction, and then continued eating the food that caused the reaction in the first place...THEN they would be idiots.
The way I see it, these folks are like the people who had the allergic reaction and went to see the doctor; they aren't trying to eat more of the food.