I think the whole appeal thing isn't really necessary.. I mean, if someone gets banned for a clearly unfair reason, more than likely other members will speak up. It's happened in the past, and even the admin who did the banning realized they accidentally banned the wrong person, or whatever the case.
It's a nice gesture but on the whole I think the admins usually make the right decision when it comes to banning someone. I think the only times the members ever argue with the admins about banning someone is when we think someone SHOULD be banned, but they aren't.