It is really rotten fruit either way -both activities are immoral and evil.
Homosexuality (the disordered condition -all causes unknown -in some cases not chosen) is not legal or illegal -it is a disordered condition subjectively claimed and not objectively measured -as such, the disordered condition that predisposes one toward homosexual activities can not be legislated for or against. Regardless, the Church teaches that those that suffer the disordered condition merit just discrimination; e.g. banned from military service, banned from Boy Scout leadership, and in this case banned from ordination...
Homosexual activities (always a choice), on the other hand although disordered and always intrinsically evil are legal in some locals -in the US, the evil of sodomy was legalized by judicial fiat recently...
I believe that any sexual activity outside of marriage, whether it be heterosexual or homosexual, is just as abhorrent in the sight of God. The difference is that somebody who wants to engage in heterosexual activity has a sanctified avenue through which to engage their desire--marriage.
But if a person with homosexual proclivities is celibate is he or she anymore guilty of a sin than a person who lusts after a person who is not their spouse?
Frankly I have less problem with a celibate homosexual being a parish priest (and presumably living alone) than I would have with a homosexual priest living in a monastery where he is living so closely with other men. It's like having an alcoholic working as a bartender.