You dismiss "old holy books" because they also include moral teaching. Thats the thing about atheists, they reject moral teaching for the masses in favor of "reason and evidence" that supports all sorts of debauchery and moral decay.
As far as schools being atheist organizations, they chased God out of schools 60 years ago, and schools have gone downhill ever since. Now all you read about is teachers being arrested on a daily basis for sexual misconduct with students.
The "old holy books" are dismissed for their immoral bull shit, not because they have some morality in them. Its nice that it says do not murder, but it then tells you to kill a woman that has been raped if she went alone in a city and did not yell loud enough when being raped. Great little stories those eh?
Now, if you want to compare sexual misconduct with minors, then lets compare one large institution vs US schools. The Catholic church I believe still has god as the main focus, yet, they sure love them some kids. So what happened there? Muhammad fucked Aisha around what, 9 or 10? God was where then?