> Why do you feel anonymity is important on this board?

You shouldn't start by assuming we feel that way!
In fact, you don't feel that way yourself: you chose to use a limited use handle to make it more convenient to identify who's talking.
There are a few overlapping groups of users who know each other through stable identities : the IRC channel, the Steam group, the Minecraft server, some guys on Twitter, the creative projects. The messageboard is no longer all of SAoVQ. But of course, there are also people who choose not to interact with VIPPER with an identity, at all.

I think not using names unnecessarily is a cultural norm we do not challenge because we like the side effects. It's a pressure-free environment. Not a license to be a bad poster, just giving you the chance to say things, disown them immediately, and forget you said them.
See for example http://www.secretareaofvipquality.net/saovq/kareha.pl/1286213227/487 . Or just re-read a 2 years old thread where you made a lot of posts. Do you remember with perfect accuracy which posts are yours? It's hard when there isn't a little picture reminding you of who said what.