I heard it put this way, which makes sense to me: If it's legitimate to change your body to conform to your mind, why wouldn't it be legitimate to change your mind to conform to your body?

Changing your body also seems a lot more irreversible than changing your mind.

Easy enough. Tell people to work out their own problems instead of going to therapists. If we are going to get into what a doctor can or cannot say, then this is as good if not a better solution. Why is it better? No medical system or insurance. If a person kills themselves due to a crisis, well then, I suppose humanity will eventually reach a point to where that issue is no longer present. After all, for thousands of years, nobody had therapists.