I'm quite sure that SSA has always existed. I'm also quite sure that a respectable occupation with lifetime security which relieved men from the "why aren't you married" question has ALWAYS been overpopulated by those burdened with SSA.
The difference, now, is that several generations of men with SSA have been conditioned to affirm the proposition, "This is who I AM", as opposed to "This is what I am tempted to DO".
Men who affirm the former proposition cannot function honestly as RC priests, but since a lot of them are in that line of work, enormous problems have been engendered.
My understanding of the CCC is that it still affirms the "this is what I am tempted to DO" analysis of SSA, but the USCCB bishops are constantly flirting with the "this is who (I) they ARE" model.
As long as there are significant numbers of bishops and priests who (secretly) affirm an heretical view of human sexuality, this problem cannot be resolved.
The "modern" view of SSA, in an ecclesial context, is actually an organized, major heresy. Like all the other Christian heresies, the belief in this key "knowledge" looms larger and larger in the minds of its proponents until it becomes central to their being.
And, like all the other major Christian heresies, it is going to have to be extirpated from the Body of Christ before the Body can return to health.
These Bishops are also the ones who were enamored of the feminist movement, and were like sails in the wind when it came to experimenting with the Liturgy. Fortunately, for us here in America, those men are either retired, or near to it. The younger Bishops who were more recently installed by Pope John Paul II, and, I daresay, will be, by Pope Benedict, seem to be more faithful to the Church's teachings, especially on sexuality.
John Paul II had a problem with folks accusing priests or Bishops of practicing homosexuality because of the tradition in which he grew up. It was common practice in Poland to accuse one's political enemies of being homosexual in order to advance one's own star in the ruling firmament. The Pope was very sensitive to accusations because of this ingrained idea, maybe to the detriment of we in America who DID have a problem with this. I believe that Pope Benedict will steer the Church everywhere, but especially here in America, back on course.
That may be true, but it seems like in the old days there were at least equally many Fathers who conducted scandalous affairs with women, many of them married parishioners who came to him for counseling.