I have a question about the Aztec's and their calender?

In mythology and folklore, I must have seen hundred to a thousands times, the question as will this world end on the date the Aztec's set forth..... Now I have to ask myself why are a bunch of modern people worried about what a primitive tribe believe... For are the Aztec's the same tribe that thought that a lunar or solar ellipse means that so monster is trying to eat the this world?... Aren't these the same native people that belived that seeing a comet means total destruction for this earth.... Aren't these the same people that belives that an earthquake is a giant snake trying to excape from the underworld... And yet Thousands of people are worried if their prediction of this world ending is correct...... Now I am not saying that we won't have an earthquake or that a comet won't p the earth or that we won't have a solar ellicpise.. But I am totally sure that their idea of a earth ending event is not even close to being anything serious that the current human race will have to