I think it is important to curate it, but I applaud the idea. I would say; only allow people with over a certain karma score on HN (>1000)? That way you benefit from the quite strict moderation here.
But indeed I remember the days on vBulletin forums; all my remarks against ‘you cannot make friends over 30’ that I uttered here come from there: most my current friends and one of my best friends I met on forums. It just worked well.