I think it is that you get far more power in who you surround yourself with and you learn better how to navigate social issues. Also, people are great at faking at being nice... I live in the South (USA) and lots of people seem really nice until they switch to a topic like homosexuality, at which point you find their beliefs are really quite harmful (things like seizing children and force conversion camps). You learn to avoid the topic and keep pretending everything is nice, but when the person things you or perhaps a friend should be in prison because of who they find attractive, I find it hard to describe them as nice. And heaven help you if you are part of an interracial couple.

In short, it is us vs them mentality all the same, and while it is really nice when you are part of the us, it is horrendous when you realize you are actually part of the them.