I see things differently.

Nicks help me quickly identify wheat from chaff. For example, I know Sling is a mass poster, so I was able to do some things to make his posting life a bit easier. When WAHa comments on code or physics, I pay him more heed than some other anonymous. Cosmo Gunny is a friend. Albright, Shii, lolocaust, etc, etc, these people all have different meanings to me.

The reason is simple: I don't have the time to check every little fact that people post. I use a person's prior history as a heuristic in deciding whether their comments are worth consideration or not.

Besides, I actually like it when people use a nick, and I gain some understanding of their persona. A mass of anonymous hold no interest for me. I'm a social being, so identities, however tenuous, mean something.