Oh dear God, I read only 1/4 of the review and I feel like I've lost several IQ points. Yes, perhaps they were crude, but unlike Dr. Harris, I find no value in the philosophy mocked by Fashionable Nonsense. Even reading about that kind of postmodern philosophical claptrap is pretty devoid of value (which is probably why I never managed to read all of Fashionable Nonsense).
But yes, he's a mathematician, I agree.
He finds possible value in the philosophy that it mocks, and points out the general crudeness of the authors' attitude and approach. I think his review is well worth reading.
https://webusers.imj-prg.fr/~michael.harris/Iknow.pdf