You're allowed to discriminate based on personality by law, but socially, if you do it with anyone you don't agree with completely:

1. You probably don't have many friends or

2. Your friends are not very diverse

Outside, in the real world, I can sit and have a very pleasant conversation on TV shows or Lisp interpreters with someone with terrible ideas or belief which are inconsequential to the matter at hand and are not part of the conversation. I can sit for a beer with childhood acquaintances that I know are racist, bigots or generally idiots, because we're talking about something else than the things I know we don't see eye to eye. And that's fine.

It is frightening that we're forgetting how real people outside the Internet are, behave and can get along in all their complexity.

Yeah, but it's a bit like to refuse to work with someone who follows a different religion than you, or someone who is into astrology a bit too much.

Again I know it's not black and white and everyone has different red lines. If someone treats killing baby mammals as their favorite form of entertainment I probably can't work with them.