In ~200,000 of human evolution, guns have been available for humans to kill each other for only ~700 years and the extremely high killability of guns has only existed for ~115 years. That is not enough time for physical (including emotional) evolution to cause humans to use guns in such a way as to insure their survival.
The professor's pablum provides a unique view of history and science in an attempt to support the professor's anti-gun argument. Taking his conclusion further, we should consider that automobiles have been around for only about 344 years. Death by automobile coincidently also has only existed for about 115 years. So by the good professor's logic, humans are not anywhere near evolved enough to drive cars responsibly.
I wonder how the author feels about the common suggestion to treat guns like cars.
Come to think of it, Dr. Roper is probably not a fan of the flush toilet either. Humans have had less time to evolve to its use than we have with guns.