There is a good chance that most of the commenters so far in this thread do not have children ion public school, did not attend public school and are not on their local school board.
I attended public high school for secular subjects and Yeshiva high school in the morning for religious studies. My mother was a public school teacher, principal and retired as Asst Supt. of Schools.
I served two terms as an elected member of my local Board of Education. 4 of the 6 members of the BOE were parents of children in the schools. They had and have a say in curriculum.
Our school board is up for election this Tuesday. There will be 8 members (no more than 4 form any party may serve). of the 12 candidates 8 have children in the schools, the other 4 have older children who graduated already.
The curriculum committee and the curriculum director annually reports its plans to the BOE at a PUBLIC hearing. Parents may comment and challenge the proposed curriculum (and they do). Only after the hearings may the BOE adopt the curriculum for the coming year.
Parents and taxpayers have a voice, but only recently do they show up and make their opinions heard. For many years, few people showed up and spoke or asked questions at the public hearings.
For democracy to work, you must participate, not just gripe on line.