Yes it is bizarre that some otherwise bright people, including even a few with relevant qualifications, buy into this rubbish. I am no expert on the psychology of self-deceit and self-delusion but ultimately that is where the answers must lie, after all they are still human, and therefore subject to human psychology. I certainly believe that those with relevant qualifications are consciously lying, to themselves as well as their audiences. They must know full well that what they believe is bullsh!t, and I have come across plenty of outrageous fibs when investigating their claims. Of course 99% + of the scientific community reject creationism outright, and just those PhD scientists called "Steve" alone outnumber all creationists combined (Google on NCSE Project Steve - I'm on the Steves list). There is, in fact, a well established inverse correlation between intelligence and education on the one hand, and religiosity on the other. The more intelligent and educated a person is, the less likely he/she is to be religious.
Re C-14 dating, it has been correlated with tree rings as far back as 14,000 years. Some of that work was done in Belfast on Irish oaks! Google on dendrochronology and the Belfast curve.