Actually it is not a cabal. It's economics and good marketing. The original intention of a psychiatric assessment was purely for co-morbidity issues and to determine if there were any underlying metal disorders which caused the patient to believe they were cross sexed.
This assessment was simply that nothing more. In the early 1970s the "industry" discovered that they could offer services to "guide" people through self discovery process. The number of TG who wanted to transition rose as a result. In today's world you have long term counseling that most often results in hormones being taken, netting (instead of three sessions necessary for an assessment) a massive amount of money to the treating psychologists, gender therapists and psychiatrists. It's simple 3x150=450, 24x150=3,600 or even more. The focus of what needs to be done has shiften entirely from assessment to guiding "self-discover". And the longer the treating specialist can maintain the guidance role the better it is. The result has been a steady accretion of more and more people who are "guided" into gender related pathologies and of course more and more of those transitioning who otherwise might never have done so.