Anarchism

Several times in their life a person learns that something they were taught to believe is bullshit. For example, one may buy into the idea that their own country is the best and their enemies on the global stage are pure evil, only to later learn that life is more complicated than that. Thing is, there is a phenomenon I've personally witnessed where a person confronted with one of these realizations overcorrects instead of actually learning the lesson about nuance. In the above example, this person would adopt the idea that their country's enemies are the best and their own country is evil. They still see the world in black and white just as before, but with the roles reversed. They're so angry about being lied to that they'd uncritically accept the propaganda of said enemy at face value, refusing to consider the idea that they might also be lying because "the enemy of my enemy is my friend".

I'm certainly not an expert on human psychology, but I think this could explain why people end up in these spaces.