Which is exactly what most people want. They want to find people with similar interests and share ideas. Don't go to the anime subreddit expecting to find anyone who's interested in a negative critique about anime.
That problem with Reddit also applies to HN and every other "moderated with a light hand" discussion forums today. Don't go to Hacker News to speak positively about 'System Integrity Protection' or 'Sealed System Volume' on Apple computers, or to consider how the GPL might be harming open source, for example. The comments will be a tire fire of people repeating the same handful of hostile viewpoints as top-level threads (rather than upvoting that which they agree with), drowning out rational discussion and driving away anyone who doesn't agree with their viewpoint. The conversational warfare tactics are exactly the same as those used on Reddits about anime, video games, and all other topic people feel strongly enough about to create a forum for and allow participation of this nature.
They were like email, except to the forum's address instead of someone else's personal address. Lots of RE: RE: RE: just like in email, lots of third-party 'forum' clients that parsed QWKmail packet downloads from the BBS and displayed threaded conversations. Moderators could remove posts from the forum, unlike usenet.
Structurally different. Take a look at the many Discourse groups around today. There's none of the same pile-on tendencies that Upvote based sites like HN, Reddit, and Lobste.rs has. There's nothing to gain by piling on usually, since there's no karma-with-the-crowd.
this threaded view so much better though. maybe sort by time instead of votes would be better. once you got through a few pages message boards got unreadable