School fails Christian girl for not saying Islamic prayer

I'm reminded of the time or two I ran into this attitude in my science teacher days.

I was once doing Big Bang theory and had a student, 17 or so, tell me she didn't believe in the Big Bang because she believed god created the universe.

I told her I didn't really care what she believed; my job wasn't to make her believe anything at all. When she questioned that I told her that what she believed was irrelevant to me; my job wasn't to make her believe the Big Bang theory, it was merely to make her understand it, and why scientists believed it. "After all, how can you possibly reject Big Bang theory with any confidence if you don't actually know what it is?"

It's similar here. As an atheist, I want everyone to be an atheist. But as a teacher, I wouldn't care one iota what my students believe. But if they're going reject islam, shouldn't they actually know what it is that they're rejecting? How can that possibly be unreasonable?