If I'm understanding well, by backlash you mean a negative view about Columbus' actions against indigenous people at the Caribe, who were forced to work hard and died very fast because of his race (skin color and physical appearance).

Columbus and his partners were not "racists" as we understand it nowadays. They believe that indigenous people were different, but they didn't know what exactly they were or where they came from, because of the big differences in costumes and behaviors. At some point, Columbus thought they weren't humans at all and that is why he wrote about people with tails or cannibals.

Also, spaniards, and europeans in general, mostly classified people by religion (Christians, muslins or pagans) and not by "race". I have read different chronics made in this period and every time spaniards met an indigenous town they asked for what gods were worshiped. It was also a way to understand how much civilized was an indigenous tribe or kingdom and, according to the information, they decided how to act (declare a war or make a deal, for example). It also had legal consequences.

As much as caribe's indigenous didn't show any sign to be "civilized", Columbus and his crew only focused on taking the gold and didn't care about lifes. We must also remember that epidemics contributed strongly to weaken and kill most natives. Only when explorers and scholars increased their knowledge about natives civilizations, the spaniards also changed the treatments to natives.

All in all, the backlash may be true if we only consider that Columbus was a kind of killer who only cared for gold. But, it wasn't something exclusive to Columbus and other people would probably do the same or something similar. Also, the backlash is not true if we consider Columbus as a "racist" because the world wasn't divided by "races" at this time (this word actually had a different connotation).