I don't see how this deals with grudges because I am talking about the psychological impact on someone who knows that it will be known they did the downvoting, not the psychological impact on the person getting downvoted (plus don't underestimate the long memories of some people who will still remember who downvoted them a long time later, after they have their own downvote privileges). Also, people who downvote currently have the option of leaving feedback by simply replying. So I don't really understand where you are coming from.