Me, too. Unfortunately, while treating a person for mental illness is the right thing to do, it requires a lot of work over the course of a long period of time, success may be long in coming, and the fees for service may not be all that high for the amount of time invested. OTOH, mutilating a person can be done in a relatively short period of time and results in a huge payoff for the amount of time invested. Plus, if the person decides to have the genital mutilation surgically repaired (as I read that a percentage of people suffering from "transgenderism" end up doing), there is another huge payoff.
In the case of many types of mental illness, I am not sure how much of the illness is a result of odd ideas that the person somehow picked up along the way, or of actual brain disorders. In the former case, therapy should be of great benefit.
Giving them the surgery doesn't mean they won't still need the therapy.
That's a big question, and it's not politically correct even to look into the answers. If the problem is "odd ideas", then therapy should help a man with those ideas to accept the fact that his anatomy includes male parts. If the problem is brain chemistry, then I would expect the right medications to help. If the problem is a physical disorder, then it's harder to treat, but there may be either a form of therapy or a chemical that can help the person to adjust to the disability.
We have, for some bizarre reason, decided to treat the problem as the body not matching the brain, not as a physical/chemical/emotional problem in the brain, and sadly we're not even considering how to treat the real problem. I'm curious what the real answer is, but we'll have to wait until the hateful left moves on to "help" another group before we even look into how to help these people.