Some parents are crack-pots whose opinions should be ignored. This is done quite commonly, and is nothing new. While I am quite the supporter of parental rights, there need to be some reasonable limits. To demonstrate with an extreme example: if I were to suddenly decide that mathematics was a tool of satan, and I did not want anyone around my children talking about anything remotetly connected with mathematics...then what should the school about this?
The parents in question seem to have objections that are manifestly ridiculous.
Gosh, we've got one poster advocating removing children from parents who are not Judeo-Christian. Now, we've got another advocating "reasonable" limits on parental authority.
Here is a manifestly reasonable limit. When 50% of the people in the United States disagree with a certain position, maybe you ought to refrain from discussing it with their children.