Because they're idiots who think Native Americans are Na'avi.What on earth would be wrong with Native Americans using controlled burns? That's a very efficient method, and enviromentally sound, I believe. (As long as they know what they're doing, of course) Doesn't it reduce greenhouse gases as well?
Most of these idiots don't even know jackshit about colonialism. I've read some of them commenting about the whole Notre Dame fire, and saying, "who cares about some old symbol of colonialism?" Despite the fact that the cathedral was built long before colonialism even existed.