Apparently according to some who have commented on this series, every single indigenous American back in the 1500s practiced blood rituals and therefore that immediately renders every single one of the millions of indigenous Americans that lived back then as savages.
Following that logic every European was to blame for those responsible for burning witches and heretics at the stake, killing innocent people via Inquisitions, Roman gladiator blood sports, etc.. Every European can be tarred as a savage for the actions of a few people. It would be akin to blaming the average person in Spain for the gassing of Jews by the Nazis.
It is still highly contentious whether blood rituals existed based on so-called evidence that relies heavily on conjecture by academics and interpretations from various artefacts.
Assuming they did occur the majority of estimates bandied about by some academics are based purely on conjecture of some archeological findings that are open to a myriad of interpretations, and not on hard tangible evidence to support the views that indigenous Americans (especially those south of the US border) were basically blood thirsty savages committing mass murder either every day of the year or on a particular chosen week.
Any person with a modicum of common sense would realize that these numbers are simply not believable because the logistics involved to carry out an 'event' of this size and nature would be insane and astronomical.
The logistics even for a current modern society with the available tools to pull it off (electricity/power, machines, cars, guns etc..), would still pose a considerable challenge much less a civilization that existed 500 years ago.