I think if the OP wants it closed down, then fair enough. Other people have the option to not read it/comment. This has been my approach. It's not a nice thread but I don't agree with censorship unless a law has been broken.
I see your point and not having read past the first page I take your word that things are getting nasty over there. I do feel sorry for any innocent person who is getting horrible things said about them. That said, grown adults have to be responsible for what comes out of their own mouths and have to live with the fallout. If they are being libellous then MN would be right to pull it. If not, then I think it would be better if people simply refused to post on the thread as a show of disgust at the content.