"Isn't the important thing to cut the rates of abuse in the Church, then there would be no need for any sort of cover up."

There is never any "need" for a cover-up on the contrary there is always a "need" for transparancy. Other organisations like the education system deal with abusers properly. You're never going to utterly eliminate the abuse of power by those in power either, however many checks are in place, there will always be those who will slip through. Thus it's essential that any organisation that others are expected to trust in, demonstrate they are trustworthy by dealing efficiently with such problems - rather than trying to cover their own backs by offering silence, protection and shelter to depraved and dangerous individuals.