Ken Ham & his ilk have been teaching for decades, explicitly and repeatedly, that if you do not buy into their specific 6-day literal interpretation of Genesis, then you might as well be an atheist. [0] This line works great to rile up the faithful, but...
Fast-forward to today, and you have an entire generation of young adults who can no longer square YEC with reality, going: "Huh, I guess I'm an atheist then?"
Ham-flavored fundamentalism rules huge swaths of orthodox Christian tradition out of bounds, and it's been devastating for the future of the American church.
[0] https://www.au.org/blogs/wall-of-separation/a-flood-of-nonse...