I think the larger issue here is that the US government MANDATES that children be taught (and, via testing (linked to funding) in many states, learn well) all subjects which are determined to be 'necessary to their education.' The primary problem I have with this approach is nearly the same problem I have with pure democracy: who chooses what is necessary?
In a pure democracy (PD) (not a representative democracy (RD)) all citizens would vote on all issues. This would avoid the 'package deal' approach of RD -- you want issue A resolved in approach A1, so you accept your candidate's view on issue B, whatever it is. However, realistically, people do not have time to both vote thoughtfully on every issue every person raises AND hold a job AND raise kids AND relax, etc. So, somebody would have to serve to CHOOSE which issues merited a popular vote. Thus, the decisions become subjective -- arbiter A believes that a rewording of a former proposal regarding drug legalization is redundant and drops it, but believes that a rewording of a prohibition proposal is, in fact, worth a new vote.
I'm going somewhere with this, I promise.
In schools, somebody (or some bodies) make decisions on what deserves to be taught. I agree that creationism of any sort does not fit the science charter -- in fact, it doesn't fit anywhere. Some bodies have made the decision that science is important and religion is not. Mathematics is important, music is (more and more often, unfortunately) not.
Let's say I think that my child's religious upbringing is more important that his knowledge of a second language... as a parent, I cannot pull the strings to get my child a comparative religion class instead of the school mandated French and/or Spanish all kids get in 8th grade (at my particular school). Even if I follow the recommended approach, and proposition the school board, and somehow manage to get the class approved, some bodies at the federal level may decide that the class is not worthwhile and shut it down.
Back to the topic at hand: the powers that be have made it all but impossible for my child to learn what I think is important. Maybe that's why everyone blames "the system" for the failures of their children -- after all, the system's taken many of the most important decisions right out of their hands.