If you just read the quote in the article it does look a bit silly. The reason why people warned him and why the field of history was so "eurocentric" is becaus

If you just read the quote in the article it does look a bit silly. The reason why people warned him and why the field of history was so "eurocentric" is because it is extremely difficult to find evidence in the Amazon. Nobody doubts the existence of Tenochtitlan or Cuzco because we have both written sources and archeological evidence. In this context, complaining about eurocentrism does come across as motivated reasoning.