What a lying manipulative sociopath. His clinic has diagnosed more childhood "gender identity disorder" than any other, and he claims to have cured some? Sounds like he stacks the deck, and "cures" some that never were transgender. He also claims to not believe in changing sexual orientation, yet pushed a study on gay "reparative therapy" through publication without peer review, that was later disowned by the author.
He is also of the opinion that transgender people are just extreme homosexuals, yet claims to not be changing sexual orientations, just their behavior to act straight, and be happy... and privately tells parents that he can in fact prevent homosexuality as well.
He lies about his methods and aims, he engages in confirmation bias, and uses a "diagnosis" that is intuitive to the most ignorant on the subject. He enjoys an influential position, only because he lies about his true opinions, motives, and practices.