I think that all the meta discussions on here about the quality of HN have become a big part of what HN is. HN is a place for hackers to discuss anything that interests them; so of course that's going to include the discussion about their own community and how to make it better.

I think you're right that we have to accept the change in communities' interests over time, but don't forget that one of these interests hackers have is to improve their own community.