Evolution vs creation:
God is abstract. He doesn't often show himself. In general, the idea of a god or gods is pretty hard to think about.
Apes are concrete. You can see them. Generally, the whole ape concept is easy to get your hands around.
It's funny that the supposedly unsophisticated ancients would all choose to believe in an abstract concept rather than a concrete one. If you asked Adam where he came from, why would he say "God must have created me, I've seen Him around the garden" instead of "I was magically transformed from one of those apes over there"?