Strict moderation is the reason HN is the only reasonable discussion forum remaining on the internet. I wish good moderation was a skill that more people learned - would you ever be interested in writing a guide or teaching a class on moderation?
Not at all. It's rather the community that makes it a reasonable discussion space. Most people here understand that this is not Reddit and that proper answers are needed when you interact with other members. Of course moderation is useful and necessary in certain cases, but it's certainly far from being the key factor here.
The community helps... but someone needs to be doing some policing to limit the effect of the bad actors or the community starts to get pissed off/wander off/degrade into pettiness.
in many discussion forums... that are not HN. There is only one HN, so you can't make comparison with other communities out there.