Many years ago towards the beginning of my career proper in technology I first came across the phrase "the September that never ended." Asking a close grey beard he chuckled, explained poetically about newsgroups and finished with the anecdote that when he first started his career he had come across a similar phrase, asked a similar question and thus the cycle was complete.

That's funny, I was going to make the post about eternal september, and compare HN to /. and /. to USENET.

This comment made my day.

It is all about your community and once it becomes too biased one way or the other, everyone else moves on.

FWIW, I think it's less about bias (as a sort of measure of noise) and more about the general quality of conversation. Even if all of the biased camps balanced each other out, the noise just becomes too much and people start looking for another forum.

Or perhaps I'm just projecting my own experiences with /., digg, reddit, et al.