He wasn't "pushing an agenda". He was telling people about how a diet he went on helped him and his daughter. He explicitly stated multiple times that he wasn't a doctor and that his experience was anecdotal.
Peterson does have a way of trying to tie all of his beliefs into a larger world view, and selling that, though. It's the same thing with the Mesopotamian gods and his beliefs about gender.
That's true, however I do think the meat-only anecdote came from a good place. Him and his daughter had been suffering from clinical depression and a host of other problems for decades and the diet seemed to help them. I think if I was in a similar situation I'd try to let other people know too.
