I really can't imagine the mental landscape of the kinds of people who propagate this nonsense nor the ones who buy into it. Psychological selection and substitution come to mind as a partial explanation, but I think that, overall, as Altemeyer describes in his book "Amazing Conversions" (regarding true believers) these people just are lower in intelligence and never have been very good at problem solving.
If anybody reading this hasn't read Lierre Keith's book "The Vegetarian Myth," they should do so a.s.a.p. since it shows clearly why this planet is truly doomed and it doesn't even matter if there are comets, HAARP-weather weapons, or Satan and his minions. A good comet cleansing would only be a good thing.