Believe it or not, Rome does not micromanage the affairs of each diocese. The bishops operate with a great degree of autonomy and the Vatican has had a hard enough time getting renegade bishops to do all manner of things.
It's not quite the absolute dictatorship many may imagine. The Pope's powers are mostly of persuasion. The Pope can plea for his bishops to do something, but many ignore him. He can remove them, but that is something like using a nuclear weapon.
They knew things were rotten but did nothing!
I don't think this has been demonstrated.
SD