We are shaped by our environment. So if we are put in an age cohort from 6 - 18 and separated from the adult world, then why should we be surprised that kids leave school ill equipped to cope with being an adult?
Here is today's choice of good writing on the poor design of our schools:
Until the Great Depression, the majority of American adolescents didn’t even graduate from high school. Once kids hit their teen years, they did a variety of things: farmed, helped run the home, earned a regular wage. Before the banning of child labor, they worked in factories and textile mills and mines. All were different roads to adulthood; many were undesirable, if not outright Dickensian. But these disparate paths did arguably have one virtue in common: They placed adolescent children alongside adults. They were not sequestered as they matured. Now teens live in a biosphere of their own. In their recent book Escaping the Endless Adolescence, psychologists Joseph and Claudia Worrell Allen note that teenagers today spend just 16 hours per week interacting with adults and 60 with their cohort. One century ago, it was almost exactly the reverse. (My italics)
Something happens when children spend so much time apart from adult company....
.... Absent established hierarchies and power structures (apart from the privileges that naturally accrue from being an upperclassman), kids create them on their own, and what determines those hierarchies is often the crudest common-denominator stuff—looks, nice clothes, prowess in sports—rather than the subtleties of personality. “Remember,” says Crosnoe, who spent a year doing research in a 2,200-student high school in Austin, “high schools are big. There has to be some way of sorting people socially. It’d be nice if kids could be captured by all their characteristics. But that’s not realistic.”