Just as we can't choose a story that every single student in the class will love, or play a song that all students like, if the public starts to choose what we teach and do not teach, we would change the way our classes work.  Teachers are professionals.  We choose selections to make our students think, debate, and evaluate critically.  One of the best methods for this analysis is to give them topics that are relevant and sometimes sensitive.  Our goal should be to teach them how to think critically.  It is hard to do that with a curriculum that is watered down by outside opinion. 

Parents are able to see a copy of what will be taught at the start of the year.  They should take it upon themselves to see if there is anything that is offensive to them and then discuss with the teacher.