By narrowing down our view of those cultures to mascots, it is part of our own history that we are insulting. I don’t know about the US, but in rural parts of Canada, the line between “white” and “native” is pretty thin in some places.
Think for an instant of the fortune we spend to go visit places like the pyramids, the Great Wall of China or medieval european castles. We’re passionated with the old stuff of other cultures! We should be able to relate to our own past, our own first cultures as much as other people do.
(I wrote a longer article about this in Sooky’s Doghouse)