The Mayans predicted nothing. Never was it in word that they thought that it would all end on that day. But just like calenders, that end after 12 months, their calender had to end too. If we were to then die, calenders would stop being made, but would that suggest that because we can no longer make calenders, the world will be destroyed the last date on the last made calender?
The Mayans are a dead race, if they had lived to see the end of their calender, they would have expanded it, but they didn't and so they didn't.
The world won't end. How many other death dates have been made, that passed, and yet nothing happened? It's not worth the time lingering on such a topic.