But honestly, that's why I disagree that the reason schools hold students to the lowest standard for some equality paradox is based in bigotry, when the most likely excuse is the true one:

Teachers just plain don't give a shit. They don't have to. The teachers in the US know damn well they're glorified babysitters so that their parents can each work during the day- or at least one parent works and the other can drink wine and watches daytime TV in peace- and because they are they know they don't NEED to teach kids anymore. You're mad little Johnny can't read, write, or even know enough about science to cook meth so he has a future in 10 years? Well, you're making the teacher work and that makes them sad, and so the teacher's union will strike and you have to actually be a parent to your kids.

With that in mind, it makes sense for why the schools teach to the lowest common denominator. Teach to the lowest common denominator, you don't have to work as hard. And if some of the smarter kids are so bored to tears by this teaching they give up trying? Fuck it, they need to learn by now your job hopes in the future are based on "1- do Mommy and Daddy own a business? 2- Are you friends and/or have something on someone in high school or college who's Mommy and Daddy own a business?" Smarts or work ethic have nothing to do with it, your destiny was foretold by the stars in the sky and it cannot be fixed, and the sooner they learn to stop trying and accept it, the happier they'll be.