Apart if you want more clicks on YouTube, I don't think it's fair to call him a sham, unless you believe every popularity is a sham, but I don't think it's the case being made here.
Also, Feynman never wrote any books. His "textbooks" are lecture notes, mostly compiled by other people.
I am well aware that he did not publish his lecture notes himself, yet I believe he had written some notes and was not improvising in front of the amphiteater every day. Let's not argue about such trivia though.