Oops, I get it now. It should decrease the sort of comment people attack HN for, but that wasn't the purpose of it. Those comments are just a subset of the more general problem of users saying mean and/or stupid things about any topic.

The real motivation for pending comments, incidentally, was simply that I found, as a user, that I didn't like reading comment threads as much as I used to. HN was an instance of me following the advice I often give founders: to build something you yourself want.