It would very hard for the government or any kind of establishment to prevent child abuse. The fact that most people didn't see what was happening to these girls as a bad thing can mean 2 things. Either they enjoy seeing little girls being made to be unhappy. Or the girls weren't unhappy at what was happening to them and therefore most people disagree with the law.
I read an article by a woman who was at school in the 70's and she said a teacher of hers had sex with the majority of girls in her year when she was about 15. Now this would be considered "abuse" today. There would be an outcry. There would be articles like this making out the worst thing in the world had just happenned.
What I find disturbing is how much journalists such as nick Cohen, David arronavich and Nigel lawson seem to get so much pleasure writing about creating the narrative that these girls are the unhappy victims of male sexual power whose lives are now devastated. Rather than the alternative narrative/paradigm that this was not that big of a deal in the grand scheme of things or that in some of the cases the girls may have been willing participants who actually enjoyed having sex with older men.