I thought the word "historian" meant a bit more than just "anybody at all."

So do I.
I have always been careful to explain what I meant by the term, and have only referenced eminent professionals.

When discussing history, you have to refer to the people who research and write it.
That is not being uncivil.

Deliberately getting a thread closed with a deluge of inane comments about the weather, to avoid being proven wrong, is uncivil.