Earlier quoted context omitted.
It's self-signed... Even if the idea isn't completely original, I would assume the writing is. Or if you're doubting the factual evidence behind it, I don't think he's presenting this as fact, despite his tone. This is the same tone of many self-help books, even those backed by "real" evidence and data who cite sources. Still doesn't mean they work for everyone. If you disagree, then don't take his advice.
I don't take claims without evidence as a rule, and he didn't present any evidence. His case is especially problematic because he is making strong claims about a fairly well-studied field in which there is not a clearly dominant theory. If he's not intending to present what he's saying as fact, he should say so.
note: I notice my writing could use some nuance. Painting an extreme is just a style of writing which helps bring across a point. Obviously there are things that are objectively less fun to do.