The same with creationism. It goes against what we know of the world, what we've learned through science.
What if there are things we don't know? What if there are forces in the universe that we aren't yet able to understand? What if "what we know of the world" changes? What if we learn something new, through science, that disputes what we thought we knew and believed to be fact?
Closed-mindedness can exist on either side of an issue.