Because now you've only covered two opinions of the countless that are available. What about other faiths? How are Buddhists going to feel studying the Bible? We could reduce our schools to complete uselessness if we honestly try to address every faith option. Unfortunately, removal of all religions for many subjects is just as problematic as fixating on one- or at least, that's my opinion.

MY answer to the original question is that I don't really value my child's opportunity to "make up his mind". Now, I don't want to FORCE his belief (because that isn't really belief), but if he comes to faith in Christ after being exposed to it all of his life, I will count that as a successful handing down of the truth by myself, much as I would the acceptance of any other truth in which I believe. The difference with faith is that there are a lot of people out there who disagree, but their disagreement does not make it any less true. And if it IS true, I want my child to believe it so it can positively impact his life.