Nina, you initially said: "...ultimately great discussion comes from relinquishing control to others" (source: twitter.com). I completely agree. But I do not think bloggers who don't support comments are afraid to relinquish to control, or are opposed to an open discussion.
I have relinquished control here. You can say whatever you'd like and invite whomever you'd like. But this space is not "open" to the world and that is not a bad thing.