To stretch that analogy: all is fine, except for "this guy's" neighbors, they are in for a terrible night. And when the crowd at "this guy's party" is heated up and collectively starts harrassing people on the street, it gets even worse.

My point: Fine indeed, as long as they "stay there". But they won't. This goes for any online community: it has effects outside of that community.

What's important is that nobody interacts or challenges one another. Otherwise, our feelings might get hurt.

This is actually crucial. When I go to see cat pics, I don't want to discuss whether Evil Jew Bankers Are Stealing America's Future.

It isn't an offence thing. It's just ... boringly dumb. It's just like I'm not going to start a conversation in this thread to review my basic backstitch.