The internet just is the perfect brewing pot for this kind of behavior, in real life you always meet different people, you can't choose whom you meet and your environment is diverse, school, workplace etc.

But on the internet you can choose to surround yourself only with people who've similar views or interests, and sometimes without you realizing you walk down a path you didn't know you had started on until you lose friends and isolate yourself. And like this sub, as if by mutations the views who got confirmed over and over again in the group slowly grow more extreme, until you can't even empathize anymore with people outside of your groups, or their arguments and will generalize anyone who speaks up against the beliefs you now hold, you'll start grouping them together with names like SJWs, or Regressive-left, or Alt-right activist, robots etc. Even if they don't identify as such.

This happens in real life too of course with having the wrong friends, or living in a ghetto, or in a neighborhood where most people only come from one specific ethnic group etc., but it can so easily go out of hand on the Internet were it is even easier for toxic thoughts to spread to children etc.

Anyway this turned into a rant sorry, it is of course also only natural, but I feel it gets so easy out of hand on the internet with people in puberty who are easy prey for those kind of things and ending in people doxxing others, sending out death-threats etc.