this would be a good idea but you have to figure out what minimum we would put on them exactly allowing any regular user to join and give rep increases risk for abuse. imagine a multi of a previously banned account negging everyone for revenge. this neg would stay regardless of whether they're banned or not. i think a good minimum is 150~200 posts AND 10~20 rep, but at that point users are already upgraded or members don't bother putting in the effort for meeting that goal