imvho lobste.rs is annoyingly managed top-down by the founder. Opinions usually have to resonate with his (and his bros) ... maybe this is just because the community isn't yet big enough to actually incorporate other sides of the bubble. The discussions I have seen him fight out, and ban people over were ugly. They usually started on the premise of technical disagreements and escalate into a war because of the founder being high on lobsters being his platform so his opinion has to be the right one ...
it felt a lot like majordomo email lists for tech/devel discussions in the 90ies. If you didn't agree with the admin (no matter if their technical points where moot) you were out (that being a poorly managed list - there were ofc many great places where it was a great place exactly because it was ruthlessly managed). But if you want to scale to these dimensions I think founder ego can clash with the growth of the platform.
For me having this behavior witnessed against some of the lobste.rs users, the platform just felt like another bro-culture I could happily live without.
What for me feels narrow might feel "more puristic" to others. But I think lobste.rs could do more in terms of creating a welcoming environment by either distributing the power a little. It's not a thing the community can do since the founder has to be OK with and embrace it. Until then I'm happy to reduce my HN addiction by just limiting to HN.
Again this was some time ago. Maybe this has all long since changed. I'd hope so.