So far as I can tell, the Catholic Church has always said officially that if you’re what’s called “gay” you shouldn’t become a priest. Also, at the highest levels the Church has always been independent enough to say, perhaps after hemming and hawing and various delays, what they think is so on important issues. That’s why you have a pope and he gets his own little country. So the bottom-line position in the recent Doomsday Document on same-sex inclined seminarians isn’t particularly surprising. For me, an aspect that’s more interesting, at least from the standpoint of theory, is the justification offered, that
The candidate to the ordained ministry … must reach affective maturity. Such maturity will allow him to relate correctly to both men and women, developing in him a true sense of spiritual fatherhood towards the Church community that will be entrusted to him … those who practice homosexuality, present deep-seated homosexual tendencies or support the so-called “gay culture” … find themselves in a situation that gravely hinders them from relating correctly to men and women.
So the basic point is that homosexuality undermines the sex-role and familial stereotypes that are part of what constitute the Church and good human relations within it, as demonstrated by the rule that only men can be ordained to the priesthood. For my own part, I favor those stereotypes, I think they’re part of what constitute every normal human being and every possible society. Still, all respectable people and mainstream authorities insist that the opposite position is part of basic rationality and human decency. I wonder how this aspect of the Instruction will play out?