Because an educated populace is harder for the ultrarich to control and abuse, because an educated populace with free time can revolt against those in power, and because as a consequence of those two things ultrarich conservatives have consolidated ownership of media and used it to defund education and convince the population that funding education is bad.
My SO taught at all 3 kinds of the school in the US, in urban and suburban areas. The pay is bad everywhere, but worst at the non-union schools. Only teachers left have no better options or believe in the religion or cause of teaching, and even they tend to leave such schools the moment they have enough experience or better options. None of this is good for the kids at such schools.
The more affluent schools can afford to hire experts and keep them. I went to a rich(er) high school and had my choice among many specialty electives and advanced placement. My SO attended a highschool that was something between prison and daycare. My friend's private school was a religious indoctrination factory. Home schooled friends were often academical average to great, all socially awkward well into adulthood, and many were taught conspiracies or outright lies as long as it fit their parents "biblical worldview".
Public school was an escape from a cult-like community for me. I'm grateful my parents were too poor to force me into an alternative until I was old enough to refuse.
It sounds like you have a beef with how citizens socialize their children into the dominant religion of the society—which is literally considered a human right[1]—and less so with how schools are funded in the U.S.
See Article 18.4 of the International Covenant on Civil and Political Rights: https://www.ohchr.org/en/instruments-mechanisms/instruments/... (“The States Parties to the present Covenant undertake to have respect for the liberty of parents and, when applicable, legal guardians to ensure the religious and moral education of their children in conformity with their own convictions.”)
American subgroups that socialize their children into community religious norms are among the most successful. For example, Mormons: https://americanaffairsjournal.org/2020/11/utahs-economic-ex....
Prohibitions on religious education in public schools—which don’t exist in many developed countries, such as Germany and Sweden—hurts the majority of people who would do better under that system.
This is the bottom line; this right here.
We're being led to a second dark age ON PURPOSE.
Plus, an "educated" populace is as easy or maybe even easier to control, it's willpower against all odds that characterizes the truly ungovernable.
However I'm curious as to why you attribute or limit this to 'conservatives' only. Is this really something exclusive or characteristic of the conservative side? At least where I am from it's the left that's more interventionist in regards to education rather than the right, that interventionism being used to make education more rigid and controlled by a biased government.
And the media is definitely not consolidated, you've got clearly two sides competing at a pretty equal level.
And two sides at equal levels? Are you living in 1979? Local media is nearly all Sinclair. All the cable networks are owned by conservatives. Even traditionally liberal newspapers like the Washington Post are owned by rich assholes taking over the editorial board. And social media in the US is now dominated by two literal fascists.
From where I'm from I'd say yes, both sides at equal levels more or less, fairly favoured toward the left, but now changing a wee bit because the left went waaaaay too left.
Europe would now seem to be shifting towards the right at some levels, but from historically (recently at least) being fairly leftist.
Anyway, aren't CNN, MSNBC, The Guardian... overtly left-leaning?
As purely anecdotical data, where I'm from it's actually the opposite, majority hippies, vegan, alternative/free education advocates, etc, and a minority of mostly morally-concerned non-left-leaning (mainly religious) people, as well as specific cases of children with special needs that simply can't adapt to public education because of external reasons (bullies).
As a matter of fact, the hardcore religious right in my country have their own private education institutions, which are quite powerful themselves.
So even the (non-catholic) Christians who homeschool because of religious and moral convictions end up being moderate/center people trying to move away from both extremes.