I think the "anon" thing sometimes happens because, as Danny says, if you are a Supporter you can see who is writing anyway (hint) so it doesn't particularly occur to you to "sign" reps.
I think it's essentially a destructive and divisive forum add-on, which is not to say I haven't used it one way or another as I have grown more used to it!
Far more relevant anyway, I would have thought, would be the Ignores (which I assume can be seen by Admins and factored into decisions about members).
Which is why it will be changed next season. If used correctly, in my opinion, it can be a good addition.