It is said there is a distinction between an act, and being orientated or predisposed to perform the act. This often comes into play with homosexuality, in defence of positions like:
Gay sex is wrong but I don’t have a problem with gays as people.
Although we oblige members not to have gay sex, that isn’t discrimination against homosexuals.
Marriage is to recognise procreative-type unions. Non-procreative type unions should not be recognized as marriages. As the latter group includes homosexual unions, these should not be recognised as marriages.
In one sense, this is obviously right. Particular moral judgements about behaviour don’t necessarily imply particular moral judgements about the people who behave this way. You can ‘hate the sin yet love the sinner’.
In other senses, though, something’s off. We wouldn’t take seriously someone who proclaimed they didn’t mind the ‘orientation’ of Jewishness, yet wanted to ban behaviours like reading the Torah, Rabbinical office, and Jewish religious services. They’re just anti-Semitic under a pretence. So what is it about certain behaviours (or sets of behaviour) of people that mean being ‘against’ these behaviours implies you are ‘against’ these people?
Identity and action
The issue with the Jewish case is perhaps this: the sort of actions listed above are intrinsically linked with being an (observant) Jew. Stopping these sorts of behaviour targets and suffocates a particular identity. This is unlike other generalized restrictions on behaviour (e.g. owning a car) that affects everyone fairly equally. It follows that which behaviours target identity depend on the relevant identities going around: if there was a group of people who found driving cars profoundly important (religious petrolheads?) then a driving ban would suffocate some sort of petrolhead identity.
The important test for liberal societies in deciding what sort of behaviour to censure should have something to do with broadly recognized harms. Neither reading the Torah or driving a car should be banned unless some reason can be found beyond moral disagreement or visceral disgust (and I think the same applies to gay sex).
Given sex and relationships lie central to many peoples lives and self-conceptions, these seem pretty intrinsic to these people. Perhaps this is partly why distinctions between act and orientation for homosexuality are seldom well received.
Two sorts of gay contempt
I’d guess folks who think gay sex is wrong might be surprised when others take such exception to them. After all, you sincerely believe (and stress repeatedly) you have no problem with those who have the orientation, but regard the acts orientated towards as morally wrong. Why are they so angry?
One sort of anti-gay view everyone rightly abhors is homophobic hatred and violence. To hold gay people in contempt as people. To regard homosexuality as some form of sub-humanity. I believe that a minority of those who are opposed to gay marriage or think homosexual sex is wrong hold this view of homosexuals, and I’m sure many of them, despite thinking homosexual sex is wrong genuinely ‘hate the sin, yet love the sinner’.
Yet in this case, acts and orientations aren’t distinct enough for that. If homosexual acts are morally wrong, then the homosexual orientation is, if not character staining, at least regrettable. Comparisons to paedophilia, addiction or alcoholism wouldn’t be far off the mark – similar as they are in being an orientation that leads one to do bad things. On this view, being gay is some sort of compulsion or pathology. It would be better if one was straight.
I’d guess most homosexuals don’t consider their sexual identity cause for regret nor, if they have a partner, will they consider this relationship some sort of psychosexual cancer that would be better off excised. For those who are anti-gay acts, the acceptable gay orientations are those disowned, demeaned, and neutered.