One thing that is different here is that this site does not need to generate (ad/any) revenue, so many of the irritating things that will be common in other forums will be absent here.
What's interesting, is that Hacker News does generate revenue in a very indirect way. By cultivating a hacker community around his early stage investment company he is ensuring there will always be top-notch thinkers and doers participating in the niche he has created. Whether this was intentional or not, I don't know, but it works well for both parties: he has a thriving community of leading edge people, and the peo…
I'm pretty sure that eventually many more really successful websites will find a way to adopt a model like that, it really is one of the best ways to marry a happy users to commerce, find some side-channel that you can exploit.
Most websites think that the 'data' they have on their users is the marketable good, google has often been said to see you, their user as the end-product. YC does it different, they see a subset of the users as the raw material to drive their bottom line, the rest are along for the ride.
It's a much more direct version of what FB, google and so on do, and it is much better imo because it is more honest and transparent.