HN would suck without dang in my opinion, but what dang does is funded by a very wealthy company that has the resource to spare and, importantly, the forum aligns with the company's interest. In particular, in the past 3-4 years as HN has seen a growing user base and more "general audience"-type content, dang's impact has been essential in keeping things from "running off the rails" as usually happens when platforms grow.
FWIW there are a couple other forums (though more niche than HN) I frequent that I feel do similarly well from a moderation perspective, but again it's usually because 1 person can be a full-time, great moderator.
Considering that's where most users go, wouldn't it be in their benefit to improve the quality there?
A person can post for 6 months and still they can't be sure about speaking their mind freely , negative karma points accumulate fast and pretty soon they'll be shadowbanned.
Once you are at -15 karma points your replies are not being seen by anybody.
Let's say you are at +60 karma points that you have accumulated in 6 months. It seems a healthy margin, but all it takes is a couple of threads in which you have controversial back and forth with other HN users and all of a sudden you can't speak your mind freely for 6 more months.
Now you have to rebuild back. Only people who post a lot and post popular content earn their right to freely speak their mind on HN.
Most people aren't willing to put up with that.
Would you, as a new neighbour, walk into the local bar and start objecting or disagreeing with the locals?
Most people won't put up with that just to be part of the "intelligentia"
Other communities like it can be found in some small subreddits, discord servers, slack channels, irc, and some of the few online forums that didn't move to Reddit (like the Two Plus Two Poker forums).
I think part of why HN stays good is they don't have a built in growth incentive (at least I don't think they do).
You can imagine if you're running a site like Reddit you might really want to keep the site as high quality as possible, but for various real reasons you have stronger incentives to grow the user base, even at the expense of overall quality of community.
I think it's a primal thing. We search for the bad because it could be dangerous, but like porn, it's easy to get trapped in it.
HN's defense is the brutal downvotes, even on small things like jokes and snark, as well as things like the ban on political content. Snark is often used as a form of attack or is sometimes just hostile without the offender realizing it.
Somehow communities like 4chan and Something Awful parody negativity. If you're too negative, it gets flipped around as a joke instead of downvoted. An example would the "navy seal copypasta", where it also gives the benefit of the doubt that it's a joke and not simply immaturity. That's probably some other defense that keeps those communities alive.
Encouraging people to be logged-out must reduce the response rate to bait, and also reduce baiting, especially if tight moderation reduces bait’s impact on sincere and productive discussion.