It's human nature, I think? But also: the way HN addresses this is kind of elegant, and it emerged partially in response to that constraint, which is kind of neat.

That's why my favorite rule for anything and everything* (online or offline) is "Don't be an asshole". If someone starts arguing against it, they're pretty much saying they're an asshole.

*Not applicable to Nations or States, or any place where people aren't free to come and go as they please.