The principal of utilitarianism says: Right acting is the acting that causes the greatest good for the greatest number. Banning hated users would give those users a disadvantage, but a big part of MSMG would profit.
The German philosopher Kant says: Right acting is the acting where you would want it to become a law for everyone. If we start banning hated users that didn‘t break the ToS, we could just ban anyone, and that would cause havoc in MSMG.