That was my point, I was trying to get folks to think, looks like I failed. If the Mayans were able to predict the end of the world, shouldn't they have also been able to predict, and therefore prevent, their own demise? This didn't happen, so it's safe to assume that their prediction methods were less than reliable.
Besides, the Mayan calendar doesn't predict the end of the world, it simply predicts a "change".. which could mean almost anything.