These presidents did NOT have that kind of social phobia, they simply were shy, and Jefferson wasn't even that, he was just an elitist.
You can not run, nor serve as President, if you can't meet and talk to people and the examples given (like Coolidge) do not fit the bill.
They have taken true terms, but expanded the definations so far out that everyone could reasonably fit in.
Thom Jefferson spent all his time thinking ... reading, writing, inventing, planning, creating ... who can do that with a bunch of people around wanting to party?