I blame Horace Mann.

Why We Lost The Republic
Tim Daughtry

Now, after years of patient effort, the teachers' unions have turned America's schools into a wholly owned subsidiary of the political left. Conservatives have complained when reports surfaced about students being taught to sing hymns of praise to Obama, or when conservative students were harassed in class, or when examples of blatant liberal bias in textbooks came to light, but somehow we allowed ourselves to write off public schools as a lost cause. Homeschooling and private schools gave some relief, but the idea of getting public schools to transmit a love of liberty and appreciation for free enterprise seemed hopeless.
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As long as the left has controlled the schools, time has always been on their side. We lost the Republic in the classroom long before we lost it in the voting booth.

It's unreasonable to expect teachers in government schools to argue against the existence of their industry. "Public education" (i.e., tax subsidization of  schooling and policies that restrict those subsidies to schools operated by government employees)  originated in mid-seventeenth century Protestant evangelism and early nineteenth century anti-Catholic bigotry. We live with the consequences of a centuries-old mistake.

Update

The terrifying thing about modern dictatorships is that they are something entirely unprecedented. Their end cannot be foreseen. In the past, every tyranny was sooner or later overthrown, or at least resisted because of "human nature," which as a matter of course desired liberty. But we cannot be at all certain that human nature is constant. It may be just as possible to produce a breed of men who do not wish for liberty as to produce a breed of hornless cows. The Inquisition failed, but then the Inquisition had not the resources of the modern state. The radio, press censorship, standardized education and the secret police have alterted everything. Mass suggestion is a science of the last twenty years, and we do not know how successful it will be.

George Orwell, Review of Russia under Soviet Rule by N. de Basily (George Orwell, Essays, Knopf, 2002).

Survivor Bias

Following links from Joanne Jacobs to Brian Caplan to Megan McArdle, we find this criticism of the "stay in school" answer to the question "How do I escape poverty?": ...

14. Not everyone likes school. I've always been struck by this passage of Orwell's in The Road to Wigan Pier:

The time was when I used to lament over quite imaginary pictures of lads of fourteen dragged protesting from their lessons and set to work at dismal jobs. It seemed to me dreadful that the doom of a 'job' should descend upon anyone at fourteen. Of course I know now that there is not one working-class boy in a thousand who does not pine for the day when he will leave school. He wants to be doing real work, not wasting his time on ridiculous rubbish like history and geography. To the working class, the notion of staying at school till you are nearly grown-up seems merely contemptible and unmanly. The idea of a great big boy of eighteen, who ought to be bringing a pound a week home to his parents, going to school in a ridiculous uniform and even being caned for not doing his lessons! Just fancy a working-class boy of eighteen allowing himself to be caned! He is a man when the other is still a baby. Ernest Pontifex, in Samuel Butler's Way of All Flesh, after he had had a few glimpses of real life, looked back on his public school and university education and found it a 'sickly, debilitating debauch'. There is much in middle-class life that looks sickly and debilitating when you see it from a working-class angle.

It's still true: the mania to get more and more people into college is the brain child of people who think that school is fun, and that anyone who doesn't go is being deprived of something like a trip to Disneyland packaged with a job guarantee.
Lots of people think school is rather miserable, and they wish to leave as soon as possible. Unfortunately, the "school is fun" crowd has made an education a virtual pre-requisite for a stable and well paying job in this century. If you don't like school, and aren't good at it, what do you do? Spend the rest of your life popping chicken tenders into the deep fry at Popeye's? Or deal drugs?

McArdle might also have observed that the people who get elected to office and those who compose education policy are good at school. School worked for them. A strong element of self-flattery contaminates school policy prescriptions. Legislators and policy wonks would discredit their own credentials if they doubted the value of school.

My sisters give me great books for Christmas. I had forgotten Orwell's criticism of school in The Road to Wigan Pier.