Seems to me confession is a red herring. Anybody in the Catholic hierarchy who actually *wanted* to see what was going on could find out easily by other methods - in particular, by listening to the victims. There will be very few instances where confession provides the only evidence of wrongdoing.

There are secular versions of confession where there is a pretty clear benefit from a para.1467-type policy. The one I have experience of is in Re-Evaluation Counselling (the whole organizational structure of which is modelled on the Catholic Church) and they may have got it from Freudian psychoanalysis. Telling somebody with illegal impulses that they can't seek counselling without dobbing themselves in is a recipe for bottling stuff up to a point where something murderous happens. Sadly, counsellors are now obligated to act as detective sergeants under UK law.