Many communities start out nice and well meaning, but at some point devolve into a Wild West. HN did not, and I think that’s thanks to dang’s moderation (and pg’s at an earlier time)
Also, “small” things like dropping the vote counts, and having canonical rules for titles (which are, as pg noted, a “commons” but treated in other platforms as a land grab) reduces competition and bragging rights. Doesn’t seem like much, but it’s part of what keeps the people looking for conversation here, and those looking mostly for signaling and gratification out.
Mies’ work wasn’t without flaws or detractors, but then compare one of his subtle, perfected masterworks to the infinite cheap and nasty boxes that leveraged only the sketch outline of his style.
Now translate that into any field, absolutely including online community building. There’s no question where HN stands.
Also the really controversial topics tend to get flagged.
Facebook and Twitter desperately need moderation - but they're built completely differently and much larger. Moderation there will immediately be compared to censorship, which Twitter and FB are afraid of because it threatens their money.
We're so afraid of one good idea being hidden by moderation that we allow thousands of bad ideas - which eventually create a hive-mind and drive out the good ideas anyway.