If you penalize and normalize website censorship because of bad actors then what's to stop a big company from barraging a smaller site with malicious users to get it taken down thus removing competition?
It's a dangerous game to play if anything. You can only do so much with the money you have. I know I couldn't stop people from commenting hate on my websites, I don't have the resources or people to deal with that. Should I be taken down for something I can't control? Do I have to have a certain ratio of content to get by? How long is the window to fix bad content?