I think otherwise he might not realize the breadth and depth at which this community disagrees with him. He is not merely expressing an unpopular opinion, he's demonstrated an inability to grasp certain basic concepts. Don't think of it as punitive; think of it as a wake-up call.
Also, according to pg, it is and always has been perfectly fine to downvote people for disagreement: http://news.ycombinator.com/item?id=117171 http://news.ycombinator.com/item?id=392347 http://news.ycombinator.com/item?id=658691