I'll have to wait and see on whether to watch it or not.
However, the violence does not terribly surprise me. The Mayans were a very brutal race. In fact, the guy who was the head of my college community group feels that the reason why the Mayans all mysteriously vanished without a trace was because God wiped them out for practicing human sacrifice.
Maybe by that same mechanism Gibson's movie career will vanish witout a trace.
One can hope.
They did not vanish, they still exist today. Visit the Yucatan and you will see many people who look like they stepped out of the Mayan carvings.
At the time of the Spanish conquest the large Mayan city states such as Chichén Itzá had fallen into ruin but the Maya were still there living in isolated villages. They fought the Spanish vigorously (more so than the Incas) and might have driven them out except for the devastation of European diseases.