Thanks for the responses re Matthew 19:12. It's a fascinating passage.
I'm clearly mistaken about the nature of the second category of eunuchs, those "made by man". These are individuals who have been deliberately castrated for duty as courtiers and servants - an odd thing to modern sensibilities but clearly common enough in biblical times. I should have figured that out myself on the basis of the passage's admonition that all three catagories are to be "accepted". A deliberately castrated eunuch is not the "abomination" mentioned elsewhere in scripture.
But also to be "accepted" is the eunuch "born from the womb" that way. Here's where the explanation in the "hermeneutics" link stretches credulity. According to that link, this category is supposed to consist only of individuals born with no phallus (lacking the physical equipment), not individuals merely born without sexual attraction to the opposite sex. That makes no sense - how many men are born without penises? And limiting the meaning of eunuch in the first category to those without the physical equipment makes no sense in light of the third category - men who've pledged their celibacy out of service to God. Such holy men are equally described as "eunuchs" notwithstanding they retain all their original equipment.
The term "eunuch" in context clearly denotes the three "acceptable" categories of men who are relieved of their tribal duty to reproduce. The issue is marriage and the duty to marry and perpetuate the tribe. Three categories of men are excluded therefrom - castrated courtiers and servants (eunuchs as we use the term in modern parlance), individuals who have taken a vow of celibacy for religious reasons, and persons "born of the womb" without sexual desire for the opposite sex.
So what behavior is "abominable"? Clearly, just what I surmised - heterosexuals who engage in homosexual acts. In every place where homosexuality is admonished, the context indicates that the sin involves the deliberate turning of one's back on the duty to reproduce - homosexual acts by non-homosexuals. But Matthew 19:12 indicates that some individuals' inability to have successful sexual relations with the opposite sex is because they are "born of the womb" that way.
That's entirely consistent with the notion of a loving God. Why should a natural homosexual - born of the womb that way - be sentenced to a cruel and empty life of self-denial? One cannot be born an abomination - not unless you accept either that God makes mistakes or is arbitrarily cruel. I reject both those propositions. The homosexual does not bear the dark mark; he/she is judged by God under the same criteria as anyone else. And so - the homosexual who cruises the bathhouses is immoral. The homosexual who stays faithful and true to his/her partner is not.