It's the old chicken-and-egg problem: you build a community by attracting new users, but new users will join only if there's already a good community. It's hard to get a community started.
Strong moderation with clearly defined goals and rules could go a long way, granted you had the resources to back it up long enough for it to become self-sufficient. Stack Exchange has some categories with strong moderation and rules. The problem with SE, in my opinion, is that posting there feels literally like working without being paid. There's almost no fun in posting answers on SE, while there is still a bit of fun posting on HN.
There is also https://lobste.rs, and I like their approach more (it's not inherently related to venture capital backed startups, and its much more transparent with the community (i.e. the concept of effectively hiding unpopular opinions does not exist there)
Unfortunately, it's also nowhere near as active - possibly because it works on invites and its often hard to find someone who will invite others.
Having said that, if anyone wants an invite, please reply here (or see my profile to email me, please include your HN username if you do that) and I'll shoot you an invite.
I can see it's a hard problem for lobste.rs to keep the level of discourse high if they let in everyone, but then, yeah, it generally sucks if you would like to add to a conversation and their attitude is "Well, get an invite from one of your friends ofcourse". Because ofcourse I'd be friends with one of the exceedingly modest number of people who have accounts there. It probably seems like a good marketing attitude to them to assume hugeness or the destiny of hugeness, but attitude puts me off somewhat.
But, yes, what you said about not being connected with the whole startup thing which definely draws a certain amount of...amorality to HN.
I like how close-knit lobsters is. I feel like I can follow discussions much easier as opposed to on HN. And yes, the community being transparent is nice because it feels like the site is owned by everyone.
Lobsters' tagging/filtering feature is also neat. Beside that, other thing I find lacking in HN is mobile experience, sure it's got optimized lately but I accidentally hit upvote sometimes.
Good discussion. I don't know anything about a many posts here (not a programmer by trade, and barely a hobbyist) and I don't work in startups. But there are a lot of interesting things that are posted here and the intelligent discussion keeps me coming back.
Low-effort 'humour' comments get downvoted here! Compare to much of reddit, which is to wade through hoards of comedy-slugs attempting to riff off each other.
High signal-to-noise ratio.
A fair number of thought-provoking posts from a lot of different angles.