I think they do care that is why we have trust system that is visible for everyone who are using this forum to check before doing a trade with other person. Upon checking that user trust system it is full of negative trust comments especially from well known users here in Bitcointalk regarding that 20 BTC that he stole, no company or individual will ever trust him again. Also i am betting that right now this person have an alternate account here so even if admin ban that account it is useless.