I don't think the quick match ban mechanic is a good thing to have in a casual game, but I understand its presence to prevent people from leaving whenever they start to lose. But I feel like in certain (absurd) circumstances, people should be allowed to leave without incurring the penalty. (200 ping server, playing against a team of four pros with only bots for teammates, etc)
(I'm sick of getting matched against squads of veterans while having only bots for teammates)