We also memorialize the good Indians who helped them: Squanto, Pocahontas, Massasoit, Sacagawea, et al. And we lamely explain how they did good by creating a "synthesis" of cultures--as if Indians gained something by being conquered.
In Mexico, the same kinds of people are considered villains and traitors. I don't know if the Mexicans have any monuments to Columbus, but the lack of monuments to Cortés is telling. These people honor Indians in reality, not as fictional characters fit only to serve as movie props and sports logos.
For more on the subject, see Best Indian Monuments to Topple.
Below: An Indian "honored" to be on a statue of "America" in New York City, even if he's cowering behind her throne.