>And the average university professor in the sciences is much smarter than the average doctor.<
Logically, this is a true statement, but not because someone with a PhD is inherently smarter than someone with an MD.
University professors represent the 1 in 100 people with PhDs who actually make it into a faculty position, while (presumably) almost everyone who enters medical school eventually gets an MD. So you're comparing the top 1% of a group of smart people with PhDs to the entire group of physicians, good, average, and bad.