This suggests that the abusers in the Church were careful not to abuse the children of parents who would have had the resources to do something about it.

It suggests to me that the children didn't necessarily even tell their parents, or their parents didn't necessarily believe them if they did. I've known both happen in the UK, with disastrous results. However, if the parents had believed and taken some sort of action, it would have been one small boy's word against an expensive private school full of Jesuit monks. The parents would have looked like fools and the boy a liar. What chance would they have in Ireland, where the authorities are known to collude with the church over such things, and the Catholic church virtually own (in effect) everything and everyone? They never had a choice and they never had a chance.