It's always going to be something that's abnormal, and gender reassignment is a lot more complex than "cutting their junk off". If reassignment will improve the mental well-being of a minority of people, I don't see a problem with it.
I don't disagree. I just think we have to be honest about how abnormal it is, and not overdo it because we take it too lightly, since as you correctly say, it's a lot more complex than just cutting a guy's junk off.
Did you hear the story about the boy whose penis was accidentally mutilated in 1973 when he was a baby? The doctor "cut off his junk" or at least what remained, and told the parents to raise him as a girl. They tried, but it didn't work out at all. He always had the feeling that he was a boy, not a girl, and he was maladjusted and miserable. He finally learned the truth as an adult and decided to live as a man, and now he actually has a wife and adopted children.
I guess this is how transsexuals feel within their own bodies. It is very sad and not at all normal, but not their fault, and I don't oppose measures that will improve these people's lives as much as possible. But we have to be very careful with it lest we do more harm than good.