I don't think trans people are so delusional that they believe they aren't still limited by biology. It's more about how they present themselves to the world and how the world reacts to that presentation. I'm sure they know they will never be biologically the opposite gender they were born as. The best they can get is appearing convincing enough as the opposite gender that they are treated by others as such. If doing so makes them happier and allows them to be their "true self" then I say go for it. They are just doing what they think is best for themselves.

Much of the revulsion seems to come from religious types that think it's an affront to God's design or sin or whatever. That is the real delusion, people that think they have moral authority because of their faith and that justifies their hate. If you aren't religious and you still think there is a reason to be upset about trans people feel free to fill me in on your rational reasoning.