TheraminTrees shows us that if we treated other subjects the same way we treat religion, indoctrinating our kids into our way of thinking from the moment they’re born, it’d rightfully be considered wrong. Possibly abusive.
So why is the practice so accepted when it comes to religious mythology?
This is an idea that Richard Dawkins got a lot of criticism for when he discussed it in The God Delusion, but the argument is as solid as ever. Kids deserve the chance to study a topic for themselves — politics, religion, etc. — and come to their own conclusions without their parents steering them in one particular direction. To do otherwise, even unintentionally, is depriving them of an important opportunity to come to their own conclusions about a subject.
(Thanks to Edward for the link)