I was caught offguard by that too. It was pretty pathetic and made for a lousy episode. I'll see Avatar knowing what to expect and enjoy the effects while ignoring the message.
If anyone saw "Slumdog Millionaire," in one of the sequences, the peaceful Muslims were attacked and murdered by the evil Buddhists. Anyone want to guess what would have happened to the movie if the protagonist had been a Buddhist and his village had been attacked by Muslims?