Dave, if a grandchild became fascinated by the French Revolution, the Armada or the fire of London, would you get them a book from the library, a local bookshop (WH Smith say), record a documentary, or direct them to Counterfire, a political website of some hard left activist group?

Why would anyone go there to learn history? All you get is agitprop supporting their class war agenda.
Your man has written no single book on WW1 history, just a political pamphlet no longer available.
How about perusing some far right wing sites for balance?
I am sure you would find some activist with views on WW1 and WW11 that also differ in perspective from the real professors.

Normal people learn history from history books.
Why do you have such a problem with that?