The short answer: because "be(ing) a dick" is highly subjective.

Apparently every law is highly subjective. We have, to simplify, “Do not murder.” but it’s waived for militaries and law enforcement.

When even the taking of life doesn’t have uniform laws applicable in all cases, why make blanket rulings on speech?

It already is, just some people want want to extend the law to force people to think & behave the way they want them to. American law covers everything necessary for every individual to live a civilized life where they can pursue happiness and meaning as they choose to define it.

Can see that happening right here; some people have been downvoting and flagging this comment thread, even though it doesn’t break any rules as far as I can see.

Why stifle discussion like this? Don’t let HN become like Reddit where the downvote button is basically “I don’t like this.”

I think hate speech is a bit like drink driving. Perfectly harmless itself but can cause follow-on real world problems that do impact people's lives - ie discrimination in hiring/etc.