If psychopathy is genetic, and homosexuality is genetic, saying 'they're both not justifiably acceptable' is a gigantic false equation. Psychopathy is as natural as homosexuality is; both happen in nature, and both are justifiably acceptable in many ways. Psychopathy is not synonymous with serial murder for instance, like most people think, and homosexuality is not synonymous with sexual perversion, rape, paedophilia or some other destructive personality trait. Lots of CEO's are psychopaths, as are plenty of pathologists; people we'd consider socially productive, who contribute positively in some way (though I could also argue CEO's contribute negatively to society in other ways).
Ultimately we need to ask what the motive is for being against homosexuality, and if the motive is 'because the bible tells me so', well that's not sufficient to give form to the opposition to homosexuality in nationally recognized law. There's no justifiable reason for making homosexuality illegal, just like there's no justifiable reason for making psychopathy illegal, or making mental illness illegal. And don't take that last sentence as some idea that I consider homosexuality to be morally equivalent to psychopathy, or that I consider it a mental illness, because I don't, but I'm illustrating the false connections people seem to make with all these buzzwords; sexual dysfunction, mental illness, rape, paedophilia, sexual misconduct etc etc.
We justify murder being illegal because murder is an act of taking the life of someone else by force; it has intrinsic reason to be discouraged and punished. Give me a similarly justifiable reason to be against homosexuality that doesn't include some inference of 'I just don't like it' or 'it's a disgusting thing' or 'it's like paedophilia' or 'dirty homos' and I'll consider it, genuinely.