This is where reddit's meta-culture was at in 2008:
It turns out that you really can't have both community and scale. The attempts end up aging differently, but inevitably, to something that the core membership doesn't want to be a part of and thus the predicates that enabled its existence stop. Its A people move on and the B people move in. This is true of every human group, subculture, or social phenomena really.
I strongly recommend reading Clay Shirky's commentary on the nascent phenomena of "social software" back in 2003:
Or consider C2's conception of it, particularly the end of it:
The Decline, the formation of cliques and factions, incidents of abuse, of intellectual violence and namecalling. The software becomes encrusted with patches and extensions, the unwritten rules are flouted regularly and the meta-rules all but forgotten. It is a time of either shrinking membership, or overwhelming growth.
The Fall, an incident, whether social or technical that makes everybody realize that things aren't like they used to be. It usually leads to a revision or addition to the software as this is the easiest thing to fix.