Sorry, but you can’t blame this on any secular notion. This has been going on for many years before the “homosexuality is normal” movement we see today.
You've got a good point there.
But there IS another secular notion which was influential, that was/is the Therapy/Treatment model.
For decades after, it seems, WWII, there were influential people in the dioceses and in the religious orders who believed that what should have been called a crime and a sin, was actually just something of a psychological nature that needed compassionate treatment.
Plus there was a widespread conviction in therapeutic circles that criminal proceedings against offenders would re-traumatize the victims: that it was pointless and cruel to get victims under oath to testify against their abusers.
Therefore, all the victims needed was money (to pay for therapy) and all the priests needed was a transfer (to facilitate therapy) + a "second chance."
The Church's legitimate interest in a compassionate approach, + loyalty to brother priests, + avoiding "re-traumatizing" the victims, was twisted into this policy of clerical offenders being sent off for treatment, paralleling the alcoholic-priest model.
In other words, it wasn't all pure corruption, if I can use that paradoxical term. There was also wrongly-directed compassion involved.
When are these so-called "therapists" going to go on trial?