I agree, especially when disconnected. A lot of hosts nowadays tend to ban for everything, even if you cant really affect it. Maybe you should leave the banability for cases as leaving voluntarily or kick by vote/afk.
Like happened to me today, I got disc after about 10 minutes. I made first blood and 2nd frag, then got disc (died for first time under tower after disc) and got banned anyway, so now I have to wait for the merciful lords of PD to come and unban me.
As for me, I have no trouble of coming here to forum and ask for ban/unban if I really feel like punishing someone (or purging myself). Ofc, it would probably mean more work for admins and moderators, but also it would prevent "honest" players from being banned for no reason.