How is it difficult to justify on utilitarian grounds? If one were both a deontologist and committed to elegance in one's theories, admittedly not the most common combination outside of ancaps, one might be in a poor place to say that one form of subjective harm must be resolved in favor of the offended party without saying so for all harms. But if you think that contingent facts matter, then you can just look at the world and see that rape produces these harms and ritual pollution does not. In fact, if you really squint you can just look and see that ritual pollution as such doesn't exist at all, unlike the brain's inborn mapping of me-ness onto a body.
As it happens, contingently, there do seem to be - even beyond sex - ways of touching people that very generally do, and do not, make them uncomfortable. The fact that there's no remotely elegant way to distinguish between the two doesn't mean not touching people in ways that make them uncomfortable is almost always a bad idea! Bad touching is bad! So this does in fact seem to apply to touching in general, with the caveats that 1) for a lot of kinds of touching a norm like "prior, verbal, enthusiastic consent is required" would be unweildly, and we can take consent as the default instead, and 2) that while there is basically never outside of contrived ethical thought experiments a really great reason to have sex with someone against their consent, there are commonly if unfortunately really great reasons to physically restrain or even kill people without their consent.
As it happens, contingently, there do seem to be - even beyond sex - ways of touching people that very generally do, and do not, make them uncomfortable.
What value of “very generally” are you using? IME there are ways of touching people which would likely make (say) a American freak the hell out but would likely be barely noticed by (say) an Italian.
EDIT: “IME” is nowhere near an unbiased sample of all human experience, so it is probably much more complicated than that. OTOH there's a female American LWer who described how uncomfortable she was when so...
David is an atheist. He is dating Jane, who is a devout Christian. They have a fairly good relationship, except in the sex department: David thinks that having regular sex is important in a relationship, whereas Jane would like to remain a virgin until marriage due to religious reasons. Before they became a couple, David assumed that not having sex was something that he could tolerate, since he liked Jane very much, and was really eager to be with her. However, as months go by, David has become increasingly frustrated with the lack of physical intimacy, and is beginning to consider breaking up with Jane, even though he is still very fond of her.
What would you advise David to do? Given my experience, I think the most common response would be to advise David to leave Jane. Some people might even say that David shouldn't have started the relationship with Jane in the first place, since he has known all along that she intends to remain a virgin until marriage. They say that, if he really loves her and respects her religious beliefs, he should not ask her to have sex before marriage. Instead, he should break up with her so that they may both go on to look for more suitable partners.
Why is it that nobody says that Jane shouldn't have started the relationship with David in the first place, since she has known all along that he thinks that sexual compatibility/activity is very important in a relationship? Why is that nobody says that if she really loves him and respects his values, she should not make him abstain, and should instead engage in sex with him? Why do her religious beliefs render her position more privileged?
Perhaps the response would be this: Well, the criticism is mostly directed at David because he is the one who went into the relationship with unrealistic views of what he can or cannot do. Besides, since Jane lay out the terms clearly before they became a couple, then she could hardly be faulted.
That is a reasonable response. But imagine if the situation were reversed: What if, while they were still discussing whether to commit to each other, David lay out the terms that Jane would be expected to have sex regularly with him? Even if she agreed, chances are that people would say that he should have respected her religious convictions. Those who criticise David might point out that perhaps Jane was very reluctant when agreeing to it, but thought that it was something on which she could compromise, and that David should not have put her in such a difficult position in the first place. Well, then, perhaps David was very reluctant when agreeing to not have sex as well, but thought that it was something on which he could compromise, and Jane should not have put him in such a difficult position in the first place.
The emotional harm done to Jane by making her engage in pre-marital sexual activity could be as severe as the emotional harm done to David by making him agree to abstain from pre-marital sexual activity, and yet few people acknowledge it, at least in my experience. Or maybe many people do acknowledge it, but nevertheless there are few of them who would admit it openly and defend David. Why is wanting sex worse than not wanting sex?
What is it about being religious that gives one the more privileged position in love?