Dennis Mangan points out that the practical uses of evolutionary theory are rather limited:
So, I'd like to ask, what job, other than the miniscule number of biology professorships, is available to someone who has learned evolution? The theory of evolution is one of those things like, say, music appreciation or cultural anthropology that goes in one ear of most college or high school students, and out the other. Knowledge of evolution is all but completely unnecessary for most any job. I know; I have a bachelor's degree in microbiology, I learned the theory of evolution thoroughly, and I have had occasion to use it exactly never in my career. Most of my fellow classmates have either also never used it, or were never able to land a job in any field related to biology or medicine.
I'd never thought of it this way, but he's probably right. Knoweldge of genetics and such is no doubt very useful, and in some contexts selection and adaptation, but one can no doubt treat cancer or breed pluots without committing for or against Darwin. Probably that's why we can run a post-industrial economy with millions skeptical of the theory and finding ancient texts more persuasive.
There's an old joke about a public lecture on astrophysics. After it was over, a member of the audience asked the lecturer if it were true that the Sun would burn up the Earth in five million years. "No, no, I said five billion, replied the lecturer."
"Thank God!" exclaimed the listener, "I'm so relieved!"
If a theory that has few immediate implications can only be accepted at the price of weakening the main textual basis for public morality, it's understandable that many in a pragmatic culture such as ours choose to preserve their moral code and reject a theory that promises no reward except a certain intellectual pleasure.
Although the evidence that evolution through natural selection has occurred is highly persuasive, morally, we are on Dover Beach or worse and have found no sufficient replacement for our tattered religoius traditions. (The tatttering is by no means due just to Darwin, and the tradition was highly flawed as applied in practice.)