I think most of them suffer from deeply rooted insecurity. Like, consider: you're BAD at stuff. You know, in your heart of hearts, that you're the bottom of the barrel.
You can accept that, or you can get swept up into an ideology that says "the subgroup I'm in is better than all the other subgroups", and then, WOW! You're automatically better than most other people without having to do anything!
There was a TED Talk some years back from a guy who was part of it, talking about how he ended up in it and got out. He was a lost kid who didn’t know where his life was going, and someone took advantage of that and gave him a place to belong. It doesn’t sound much different than the playbook of most cults and even many religions.
You can accept that, or you can get swept up into an ideology that says "the subgroup I'm in is better than all the other subgroups", and then, WOW! You're automatically better than most other people without having to do anything!