and it should be kept there
I beg to differ there. If one actually understands the point of mythology, then it would be silly to keep "it" there. The truth that is contained in mythology should just not be kept at bay. There is a reason for it, and if people actually want to take the time and read the myths for what they are, then there can be huge benefits.
It isn't as simple as naming a truth. If you actually would like to get into a discussion on the truth in the creation story, I would be happy to start a new thread. But it simply isn't a subject for this thread.
but it does with most theist
An appeal to numbers is a logical fallacy. An appeal to numbers, when the numbers are made up, is a fallacy based on ignorance.
The largest Christian sects have no problem with evolution and creationism existing side by side. So I think you may want to recheck your facts. Catholicism, and the ELCA (Catholics being the largest in the world, and the ELCA being the largest Lutheran group) both accept that evolution and Creationism can go hand in hand.
creation only opens the door for pseudoscience when it has no credibility in reality, scientifically
No it doesn't. If I recall, you believe in dowsing. Some, like James Randi, or Michael Shermer, would call that pseudoscience. But I highly doubt you would say that such a belief leaves to more pseudoscience.
If one accepts creation and evolution, why would it lead to more pseudoscience? It wouldn't. And the fact that many atheists (and I choose atheists as they do not accept creationism) accept various aspects of pseudoscience suggests that your observation here is incorrect.