During my 30-year career as a scientist, I have come across about a half a dozen Ph.D. recipients who were implausibly and alarmingly unscientific and unintellectual. They had somehow fallen or been pushed thru the cracks of their respective Ph.D. granting schools. Those characters were living proofs that a Ph.D. does not necessarily turn a recipient into a scientist. The corollary is that to become a scientist one doesn't need a Ph.D.
If there were a way to measure the scientistness of scientists, I would suspect that the distribution of the measure for a large number of scientists would follow a normal curve. The half a dozen dullards, and others like them, would be in the left-hand tail of the bell curve.
Who would be in the right-hand tail? The Nobel laureates and the like? No. The mad scientists.
The proverbial mad scientist is a highly scientific person, with or without a Ph.D., but with certain unscrupulous motives that overcome or dictate their scientific curiosities. Hence, they are in the right-hand tail of the distribution of scientistness.
The real question is, would we rather have a mad scientist than a nonintellectual Ph.D. who has no idea what it is all about?
The mad scientist Kavon (played by David Opatoshu) making his point in the episode Alexander the Greater Affair (part 2) of the mid-1960's TV series The Man from U.N.C.L.E. The U.N.C.L.E. agent Napoleon Solo had just interrupted Kavon's attempt to mummify Solo's partner Illya Kuryakin (in the background).