It's not hacker culture where I come from, and it continues only if people enjoy it with all the consequences. There's a difference between a slightly snarky exchange at the office and a forum where people come to talk about ideas. An "eat shit and die" culture might be entertaining for a short while, but ultimately it becomes self-destructive when nobody cares to post or show anything new and everything old gets worshipped by consensus.
Yes, I have no problem telling someone on ShowHN where I see the issues with their project. But that's different from a blanket "come back when you're a Rails-powered millionaire, and by the way if you're not one already you'll never amount to anything" attitude as expressed above.
There is no question that a community like that is possible, you'd just have to wait for all the "losers" to clear out. So if that's really what HN is about to you, ramp it up! But lazy malevolence is still not the same as hacker culture, if such a thing even exists as a singular concept.