Kyle

Australian Skial God
Contributor
Because the whole point of the appeal system is for people to tell the admins why they think their punishment was wrong. It's harder to do this when the actual person who was banned isn't talking to the admins directly for whatever reason. There's no reason for an unrelated 3rd party to get involved as a middleman between the admins and that person since someone who can access the servers can also access the forums just fine.
 

Denis

Sufficiently Lethal Scout
Contributor
Also if the person who is trying to appeal can't even be bothered to do it himself then it shows he is not committed or does not care enough to even make the effort to come back.