> I'm sure there are many topics that if a teacher or librarian presented to your children you would move to remove their discretionary power

I would first consult with them, and, if necessary, go to the school board if I thought they were being unnecessarily intransigent (or too ideological). In other words, I much prefer working from the bottom up, i.e. from the local community level, rather than having prescriptions imposed from the top down.