However, the Maya still survive today, so the conquistadores didn't kill all of them; all but one of the Maya cities had fallen before the arrival of the conquistadores (as the article mentions, the sacrifices at the particular site profiled ended in 900, over six centuries before the Spanish conquest); it isn't clear that the conquistadores knew about the Maya history of human sacrifice; it isn't clear that the conquistadores had any qualms about killing people they saw as fully human, or indeed abusing them in a wide variety of creatively sadistic and depraved fashions.
One of the key sources is Bartolomé de las Casas; this translation is readable but the extensive prefaces about how Catholicism is evil may give you some idea of the difficulties in getting an objective account of what really happened. If you can read Spanish, the original may be easier to read, because English has changed a lot more since that time.
http://www.gutenberg.org/cache/epub/20321/pg20321-images.htm...
> It is estimated that 90% of the indigenous population had been eliminated by disease within the first century of European contact.
Lol. That’s definitely false.