What worries me is that according to opinion polls, anywhere from 30% on up of otherwise rational people believe this young earth stuff. Stable and conscientious families are where most of the future scientists, engineers and medical people are expected to come from. We need them.
I tend to doubt that the number of people who believe in a young earth is anywhere near that high. Most of the polls on the issue ask about when and how humans came about, and there are various ways for people to rationalize an old earth with relatively young creation of humans.
This article looks at some polls that more specifically address the age of the earth, and others that avoid a religious spin to the question, and the numbers are much lower.