LOGICAL EXPLANATIONS FOR 2012.
1. Ran out of room on the rock.
2. The guy who wrote the calendar died.
3. Spaniards took over, so the Mayans cursed them.
4. The stars secretly hate our guts.
5. King Mayan took away the Calendar budget so they could have free healthcare.
6. Trying to pull a prank. ("Hey, you know, we've been working on this calendar for a while... how about we make these guys panic and end it?
7. There was more, but when the Spaniards took over, they broke it.
8. Ancient computers were made, and all new editions went digital. Then Y(-2)K occurred.
9. The writers went on strike.
10. Cockroaches revolted. In the ensuing war, all the Mayans were killed.
11. Playing cards were invented, and everyone suddenly had something better to do.
12. They're giving us another reason to hate winter.
13. Black Plague.
14. If they can accurately predict events, maybe they knew that Obama got a second term and decided to give us a month and a half to suffer.
15. They met my descendants.
16. Got depressed when they couldn't jump fences.
17. Mayans got tired of writing.
18. Mayans procrastinated.
19. Mayan calendars said they were "to be continued..." but that got erased because it made them look lazy.

I'll take more suggestions.