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.
Certainly there can be closed minds on just about any issue that a person encounters. That doesn't mean it is so, here. The Scientific method, by it's very nature, relies on falsifiability. When you bring in a creator god, you no longer need science, because your new god can explain everything away.
"Why is the sky blue?" "God made it that way?"
"How did the earth form?" "God did it."
"Where did man come from?" "God made man."
You start answering questions like that, such as Creationism does, and you eschew the Scientific method of falsifiability, in favor of whatever flight of fancy you wish to believe, without needing a single shred of evidence to support it beyond one's own circular logic.
Having an open mind does not mean having a gullible
one. Creationism, by it's nature, is a closed mind system. Everything one needs to know every answer in the universe is always going to fall back on some variation of "God made it that way". It is the device of the incurious.