That's an inaccurate interpretation of the guidelines, which make no attempt to exhaustively define civility. Exhaustive definitions are the worst thing to try to come up with, because then people will claim that if something isn't listed it must be fine.

Your statement "Zuckerberg is a very bad man" is both unsubstantive (because it's cartoonishly simplistic) and uncivil (because it's an absolute denunciation). It contains no information besides that you don't like Zuckerberg—which is very little information—and squanders it with vehemence.

The rules of civility don't suspend themselves when you're talking to or about someone whom you suspect of being bad. On the contrary, it's precisely for such situations that the rules exist. If you like someone and think they're good, you'll be nice naturally. It's when you dislike someone and think they're bad that you need the discipline to conduct yourself civilly, because like everyone else you owe that to the civic order.

Civility exists to prevent things like people jumping up with a knife at a medieval feast table. On HN the guidelines exist to prevent the internet forum equivalents.