That's bull. A doctor can be a great doctor and not be able to run a business. Would you want a surgeon cutting into you to be worrying about payroll, insurance, equipment maintenance etc. I sure as hell wouldn't and I wouldn't care if the Doctor flunked accounting as long as he was the best diagnostician or surgeon around
I could argue that Churchill never would have had a political career if not for WWII but he was an excellent war time leader
But that in no way means he was wrong about socialism