Why, Oh Why?

I teach the intro Biological Anthropology class. Evolution is the theme of the entire class, and fully half of the semester is devoted to human evolution. When students register for the class, the content is clearly stated in the course description, and we go over it on the first day of class, when I give them the syllabus.

This leads to a deep and imponderable question: Why, in the name of all that is holy, do students take this class if they don't believe in evolution?!?

This class isn't required, except for anthro majors. I've only had one anthro major who falls into this category, and I suspect she was using faith as an excuse for failing the class. Sure, the class fulfills a GenEd requirement in science, but students could fulfill the same requirement with GenChem, and with a lot fewer challenges to their worldview. And yet, a student told me today that she doesn't "really believe the Earth is billions of years old and that macroevolution happens."

Don't get me wrong, I'm not saying I only want to preach to the choir. I know that's pointless. But it's also pointless to preach to the stone deaf and antagonistic.