>>7618980this,
i'm pretty sure all (or almost all) public high schools will give the option to go at the very least through calc 2 (the end of the standard single variable calc) and the ones around here partner with the local CC to send students to calc 3 (multi variable) and diff eq if they are motivated to do so.
The problem is probably a lengthy one that can't be neatly summarized but I suspect some cycle of students not doing well because they aren't motivated, with the schools reacting by lowering standards (it's okay if you only get through algebra 2 anon, and we'll even dumb it down for you, it's okay you can retake it when you get to community college), followed by students then lowering their own standards again so that they can still just coast because IDGAF, followed by the school responding by lowering expectations yet again...etc etc etc
Remember, in America if a person/group is not succeeding, it is NOT their fault. NO FUCKING WAY. It is ALWAYS somebody else's fault for marginalizing you if you ever don't succeed. You can do no wrong. You are perfect*.
(*=if you're a minority)