A lot of the dynamics you're describing here on Hacker News also apply to Hacker News. It's the same problem: Surface quality content and don't allow the items

A lot of the dynamics you're describing here on Hacker News also apply to Hacker News. It's the same problem: Surface quality content and don't allow the items on the front page to choke out new submissions just because they're on the front page attracting all the votes.