To me, the existence of Anonymous Monk is important to lower the barrier of entry to the Monastery.
If I have something to contribute to a discussion, I don't want to have to register, wait for a confirmation email, click a link and set up a profile. By that time, I likely already have forgotten my train of thought. Being able to directly respond to a discussion is important - if I find a discussion good, and maybe find more discussions on the same site, then maybe I'll sign up. But that comes after participating, not before.