It's a great book that gives you a kick in the bum to stop distracting your self and just get on with it, he points out many different ways in which we distract our self's and puts on the pages many of the conversations we only have in our own heads and points out how we are over rationalising so we don't have to perform/do and how that's really subconscious fears preventing us.
I belive most of the negative reviews are from people who don't want to admit that's the case and instead are picking on minor elements of the book making out their huge themes when there not.
He's not overly religious he talks about a muse in the way the ancient Greeks did, he dos not say all illness is mental only points out some are as a distraction technique (I know people who have done this).
Ever way haters going to hate.
The books very grounded and dosnt really dwell on any point other than, if you want to succeed just turn up every day and persist.
Fyi there's also a Joe Rogan podcast with the author if you want to get a feel for the book before buying.