I think the philosophy is that a comment such as the above is (or should be) sufficiently inappropriate that anyone posting it here is either consciously trolli

I think the philosophy is that a comment such as the above is (or should be) sufficiently inappropriate that anyone posting it here is either consciously trolling or oblivious to his environment. If he needs to be explicitly instructed not to post that, he will also be inclined to post a thousand other crappy comments, each of which are, as Tolstoy might or might not have said, crappy in their own way. The best clarification possible is to create a sea of high-quality comments around his, so that he can contrast them with his, and learn.