To add a wrinkle to the responses to glenn and vintage's question: as a bleeding heart white guy, I can see an argument why any Native American related team name is problematic. It never seemed to originate from a tradition of, "This was the land of this tribe of people, and to honor them, we will name our local school/organization's team after it." Instead it was, "We need to have a name that shows that we are wild, ferocious, and savage. A lot of teams have already gone for animals, like Bears or Tigers or Eagles. Hey, why don't we say we are like savage Indians? That'll do it!"
That's obviously a little reductive, but if I were a member of this exceedingly marginalized group, I would assume that the widespread use of tribal names and general terms for Native Americans wouldn't feel all that different from watching old westerns about cowboys fending off attacks from the savages.
