I don't believe it but the people who did aren't necessarily idiots, The Mayan calendar is more accurate then our calendar we have today, they didn't have leap years it was so accurate. This crucial fact meant that it was very possible that the world would end. The Mayans credentials of its civilization are very high and advanced. If I wasn't a creationist i'd believe it to, however, the likely possibility is they died out before they could finish the scrolls for the time estimates. and you must remember they didn't have math-based computers that could calculate years and they didn't have paper.
It was probably chizzled into hard stone which would take a very long time. - Thus I Win Says Thy Lord Kakashi,