Leaving aside the question of how and when sexual orientation is determined -- for which the scientific evidence is pretty dubious at this point -- let's just take a similar case and see where we end up.
How about passing a law making it illegal for surgeons to perform sex-change surgery on patients -- even if the patients want them to? For sure, physical sex is determined (or rather, revealed) at birth; surely attempting to reassign it is a form of abuse?
Oh, but Art -- what if they really, really want to physically change their sex? Well, what if they really, really want to change their sexual orientation? How is the one okay, but the other abusive?
I'm not saying that anybody should be forced into any sort of therapy. Nor am I saying that every kind of treatment (medical, surgical, or psychological) is ethical. But if we can help people quit smoking, lose weight, come to terms with their families, deal with trauma, or find the dedication to succeed at (name your dream), why can't we help people who want to change the way they function sexually?
This has nothing to do with science, either biological or psychological. This is about making it impermissible to challenge the "goodness of gayness," even for a willing patient who wants for merely personal reasons to be somehow different from what one finds oneself to be. This is simply ideology suborning "science" and is the same sort of evil silliness that the Nazis used in their racial purity laws. All that is missing now is a legal regime that can punish pastors for "hate speech" (calling certain things sins). Oh, wait -- they already have that up in Canada.
