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.
But that was almost a decade ago. The mindset of the tech community has gotten far more political (not a bad thing, but a natural consequence of "software eating the world"), and it's really hard to imagine that HN would have turned out like it is today through self-policing alone.
Even if we assume HN were to collectively agree on taking a hard stance against anything political in nature (which still seems to be the case sometimes, given that the mods have to occasionally step in and manually de-flag and protect threads), that would've likely turned off a number of current HN users who see HN as a great place to discuss tech's greater implications and role in society.