If lobste.rs wasn't invite only and didn't have the invitation tree so that a single infraction banned everyone responsible for vouching for that individual up to the root, it would need downvotes as well. HN has open public membership so it needs some filter to keep the culture intact or else it would just degenerate into chaos.

Unfortunately it isn't the 1990s anymore. The internet is a sewer of bots and slop and rancid toxicity. You can't expect people to be civil anymore, or even sane. Just the baseline of common decency requires aggressive gatekeeping and moderation, and preferably keeping a community small and hostile to outsiders. I kind of hate it, it's elitist, but the alternative is everything turning into 4chan.