Perhaps Dr. Holsinger doesn't have any first-hand experience of actual vaginas, though this seems unlikely, since he has four children. Possibly his wife just didn't have the heart to tell him, and has been suffering all these years in silence. However, as someone who has an actual vagina of my very own, I can assure him that if one were to put a sharp or pointed object into one, "severe damage" would, in fact, result. It would be a very, very, very bad idea to insert, say, a poker, or a carving knife, or a pair of scissors, into a vagina. Just as bad as doing any of these things to a rectum. Really.
Maybe, on the other hand, he thinks that penises are sharp and pointed. Who can say?