You should be. It was the non or very little religious parents that did not like religion being forced onto their children in school that prompted this to begin with, IIRC.
I personally don't want any teacher or school staff teaching my kid some religion.
Exemption: IF the school is teaching the children about the religion itself, its origins, history and how it operates, that's ok. Just don't try to persuade them in believing it.
Why could the non-religious people not open a school for their children? Wouldn't that be better than having the religious pull out their children from school? Why force the religious to stop something they want included? Isn't imposing your views on another as well? And if more and more people are teaching biblical schooling to children at home instead, what exactly did you achieve? A national drop in math and science scores is hardly something to boast about.