That'd be the thing indeed.

hn is largely a technology oriented link aggregator with discussions, and probably some would also classify it as a forum. Or as social news site as goes on wikipedia among fark, slashdot and reddit. But beside a voting system, simple profiles there's nothing else - this is nearly an experience unlike anything large social network services offer.

A typical social media platform mainly exists around main stream/feed, sharing content and building profile or groups dedicated to particular topics or around known brands. That's of course the perfect unstained image because everything falls apart when we start getting into the details, such as algorithms in the work, content quality and moderation and so on.