You agreed with temp bans though. What if the player decide they ignore the ban, and come back and do the same thing again? Eventually if a player accumulates enough temp bans, a developer has to permaban them, right? Constantly banning a player costs money.
Even if the developer figures out a way to just constantly issue temp bans for no cost, how is it fair to deprive someone of something they bought just because there are aspects of the design that are scuffed and exploitable? Even then, how is it good business to alienate your most dedicated players?