I see this as a problem that WT created for itself, and must now deal with the consequences.
While true that they don't need to create and keep files on members, the fact is, they did. Since those files exist and the court is aware they exist, the court demands the files are to be turned over to the appropriate authority.
I don't recall Catholic Church needing to hand over files on abusive members, or being held liable for the actions of congregants. I seem to recall the church being only held liable for it's 'employees'.
As far as most elders not dealing with abuse, it may not be that it wasn't occuring, but they may not (yet) be aware. A congregation we had moved from had multiple incidents, with different abusers and victims. There were no warnings to the congregation, but there were more than the usual CO/DO visits as well as odd behaviour and statements made during meetings. While there was plenty of speculation among average congregants, those elders and MS's "in the know", including their friends, knew everything, and each were able to take protective actions for their family, unlike the more lowly members outside of their clique.
It seems WT are similar to Scientology as children are considered to be small adults and are expected to act as such. Not only are children expected to dress up and sit and pay attention for long periods during meetings, assemblies, and conventions, they are also expected to prepare and participate in answering during WT Study, Daily Text and Family Study as well as the preaching work including D2D and at school.
When it comes to reported sexual abuse, there has been instances a minor child is questioned by elders to determine what they were wearing or how they interacted with the abuser, thereby placing blame on the child for "asking for" or allowing the abuse to occur.
WT are treating child abuse as a sin, not a crime. Sins are within religious jurisdiction whereas crimes are beyond a religeous matter and authority.
There are those that make the excuse that laws need to be amended to be more consistent. Consider WT's claim that beliefs and treatment for all of Jah's people is consistent everywhere on Earth and that Jah takes notice even when a Sparrow falls from the sky.
If JW's truly believe WT is Jah's organization, it shouldn't matter what man's secular laws require for JWs to consistently do the right thing in reporting abuse of those that can't defend themselves. When an incident of abuse is reported to the appropriate secular authorities whether required or not, then accountability to God is transferred to the authority for how the matter is handled.