Well as a Historian, I can explain this.
“Professional Historian” are almost universally far Leftist political wack jobs. NO Department on any University campus is as wacko Leftists as the History Department. Even the Arts department is more sane then you average professional historian.
Similar bunch of lunatics also once name reagan as worst ever. It was in Time Magazine. My 88 year old at the time Grandfather and I got into a pretty good argument over that one.
My wife told me before we got to his house not to argue cause it would cause a heart attack. When we left I just said “he started it “
He loved those arguments as much as I did.
Indeed they are left wing. A friend of mine was watching tv with most of the historians in a large museum. They cheered when the Red Chinese Army attacked the demonstrators in Tianaman square. Disgusting goobers.