The simplest explanation of Prussian school is that there's high demand for the torture of children. That parents, on average, are malicious toward their children. If that's the case, there's absolutely no mystery. Clearly something like Prussian school will arise stabilize.
It's not hard to find a model for women hating children. It's not inexplicable.
Women want to fuck Chad. Chad hates women who have kids. Thus women hate kids.
What about the pill? They can just be sterile, right?
No, evolution isn't completely retarded. Women also have a direct desire for children.
But: it's sufficiently retarded. Women, on average, have a higher desire to fuck Chad. Hence they resent their own desire for children. Women project this resentment onto their children so they don't have to take responsibility for it. (P.S. When the Bible claims women are cursed, it's allegorically correct.)
It gets worse. Some women are aware Chad never wants to fuck them. "Might as well have kids I guess." Then their kids are a constant reminder of how they're too ugly to get the sex they want. (Women are absolutely obsessed with sex. So much so they're scared to talk about it at all lest someone notice. Utter perverts.) Especially if the kids are daughters who also won't get to fuck Chad. Oof.
Of course this makes something of a mystery. Why do parents on average take care of their kids? I suspect it's a reflex. Yet another system layered on top of these. When a child is threatened in front of its parents, evolution uses the status system to goad them into caring. It's not that they care about the child, they care about being embarrassed by having someone mock their dedication to parenting.
A bit strained, but this is only one mystery. Going the other way is much more mysterious.
Further, this one mystery jives well with the Prussian school == parental malevolence theory. While they can't let their kids be tortured where they can see (on average) they can certainly allow them to be tortured when they're not looking. The Regime helpfully all but bans parents from campus, so they don't have to constantly invent excuses for their negligence. Little voice: "Hey... maybe check that they're not abusing your kid?" State: "Don't worry, you're banned! You can't check. P.S. You don't...distrust Big Brother...do you?"
Luckily, the pill and abortion exist. Women who hate kids don't reproduce above replacement. Excellent. Divine. Let them gracefully exit the gene pool. The trash will take itself out as long as nobody gets all uppity with the garbageman.
P.P.S. When the Bible claims humans are inherently sinful, on average I find it hard to disagree. Lots of corroborating evidence, btw, regarding bubbles and enclaves and so on. Every time you assume humanity is more evil by default, you get a simpler and more predictive theory of psychology.