I think the root of the problem is that people give the bible so much credence. Most people who make ridiculous claims use the bible as their inspiration. Harold Camping even said that the bible guarantees that he's right. You and I know that the bible is just a bunch of superstitious nonsense written down by primitive, superstitious men who didn't know any better. But too many people take it as absolute irrefutable truth, probably because they've never actually read it.
Christian apologetics is the art of rolling a dog turd in sugar and selling it as a donut.