So you're calling a massive ancient civilization a cult now? 
The Mayans never believed the world would end on that date.
I not sure about what you said, have you ever met a mayan from a long time ago and asked him or her about this calender? so unless that is true, how would you know

. additionally as i recalled mayans sacrificed many to their "gods" to keep the rain away or keep everyone in perfect health. so its not a too distant bet that its possible they believed this prophecy.
I don't believe in self for-filling prophecies about an impending doom in 2012.