OK, but I think "cool" has a different meaning in this sense. We sometimes call lions and spiders and sharks "cool" but they also do a variety of not-so-nice things to their meals.
Mayans certainly didn't have a monopoly on cruelty among ancient cultures. I think you have to sort of accept it as part of the territory. There's a difference between saying an ancient culture is "cool" and saying you actually would have wanted to live there.
