Are you just shooting from your gut? You are dead wrong. Lots and lots have been discovered in the last hundred years, especially using MRI, about the brain and neurological gender differences. “They” did not “just change it.”
There are regions of the brains of females and males that are hardwired and distinctly different. For example the central region of the bed nucleus of the stria terininalis (BSTc) is one seat of gender differences. It is generally twice as large in males as it is in females. In transgender males, the BSTc is the same as that for women. So there is a real manifested neurological difference.
That is a scientifically based cause of transgender tendencies that was not known one hundred years ago. Transgenderism is not a mental illness. You can't change that kind of hard-wiring of the brain through therapy.