Why would gloating be an option? History. Native Americans have been depicted or seen as the menacing Other or enemy basically since we got here, so the idea that using them as mascots was somehow a compliment is just so....white. It's, like, "well, we basically annihilated these indigenous peoples, but naming our sports teams after them is a nice olive branch. We're cool, right?" It doesn't require someone actively sitting there thinking, "THIS'll show 'em" for it to be the kind of fucked up, rubbing people's face in it-thing that seems ingrained in white America when it comes to minorities. Bottom line, this is based out of the idea of Native Americans being seen as a terrifying, dangerous enemy. It's not a compliment or sign of respect.