Roots

I am now fairly sure that Blanchard's work on homosexuality as abnormality and by extension his transsexualism taxonomy are rooted in self-rejection. 

This is a very common theme in older people who grew up with very rigid norms. Lindsey Graham was one recent example and there are countless others. 

The basic psychology says "if I can't live authentically neither can you" and at the very minimum I will make sure to stigmatize you. 

This vision of the world is myopic and rejects the human mosaic which is more accurate of how society would be were it devoid of judgement, shame and guilt. 

As a gay man himself and early boomer, Blanchard would have been exposed to very negative messaging about his own proclivities. The instinct toward self-rejection would have been virtually automatic. 

Many of the patients he saw in the 1980's would have been much the same and thus he took full advantage.