Its author, Bessel van der Kolk, was fired in 2017 from the Trauma Center that he founded (located in Brookline, MA).    The parent organization said "His behavior could be characterized as bullying and making employees feel denigrated and uncomfortable".
In Facebook discussions after the 2017 firing, therapists who had met him said they found his behavior to be "arrogant", "condescending", and "dismissive".
In terms of scientific validity, there isn't a ton of support for its conclusions yet.  
I've also seen individuals in forums describe the reasons why they don't recommend the book to others: