Ethereum reverted transactions in the past when a large hack occurred. They had to stop the whole chain and go back to the previous state. I don't see freezing hacked accounts as a problem, rather a feature offering safety of users' funds and detracting hackers from trying to run expensive malicious campaigns (cheaper and more effective to scam from other blockchains' users).
My only condition would be that Block Producers hold a considerable amount of EOS, so they always have a lot to lose if they behave unethical. The more EOS they have at stake the more credible they are.