I wouldn't jump to conclusions about people based on their blind spots. The guy who invented calculus believed a whole lot of nonsense. Doesn't make him dumb or invalidate his accomplishments. Being in a PhD program is most definitely sign of some sort of above average intelligence. Irrational beliefs are not proof of lacking intelligence. People who are so ready to dispense judgement should go talk to specialists about things they hold to be true on fields they don't really know a lot about. Would be humbling.