In Canada and USA, behavioural/attitude problems are generally less of a problem in religious schools than in secular schools. Religious people have a wider spectrum of "illegal" behaviours which seems to have a taming effect on kids, because they are so strictly enforced.
The question is, do we really want tamer kids??
Yes... so... we have those in Canada and USA. I don't know the Israeli K-12 system, yes quite possibly it's worse than here, but let me tell you things are pretty messed up here too. The religious tend to keep a very uppity discipline in their classrooms, which secular institutions frown upon. One of my best girlfriends 10 y/o son steals, bullies, fights. His behaviour was getting seriously worse so she switched him to a 'nominally' religious school and things have been kept slightly more under control, but the damage was done.
I think children's behaviour is equally the result of parenting and schooling. After, the number of quality hours spent in both contexts is nearly equal. My best friend has been a Buddhist for nearly a decade and believes her son is an angel and beyond reproach and the school teachers should "know" how to handle any student. I think the religious schools are better at compensating for bad parenting. But at the cost of creating "status quo" "tamed" little humans.
I don't know the solution. I think a secular school system which functions outside of an "absolute" value system, by default requires firmer parenting. I know you don't like that answer. And of course my best friend's lack of parenting is but an anecdote...
Another obstacle to peaceful classrooms is our PC policy of complete integration of under-performing students with mental disorders such as FAS and FAE (very common in Northern Canada, where I've worked in K-12 classes) and the refusal to have students fail grades. When I was growing up, disrupting students were kept in "special classes". I see that kind of segregation as beneficial, in a limited and controlled setting.