I would agree, except in Aliens there is a clear, distinct, and consistent divide between humans (good guys) and aliens (bad guys). In Avatar… well, hell, a bunch of folks are humans, there's a bunch of aliens, there's folks that are aliens as a day job, some that want to transition from human to alien full time… and I won't even get into the whole narrative of starting as hesitant allies and transitioning to full on war with some humans choosing to fight other humans.
Interesting observation by The Oatmeal, but an excessive oversimplification.