Then this is all that matters. I do not subscribe to the leftist idea that any given person can represent the whole of their race. Natives are people, and like everyone else, their opinions are going to vary person to person. My great uncle was a fan of this kind of stuff, seemingly ironically, because he derived entertainment from things like the idea of the Redskins playing against and beating the Cowboys. He also didn't mind the name Sioux. Oh, by the way, a lot of the people collectively known as the Sioux don't actually like being called Sioux, because it's derived from a slur basically. But again, it depends on who you ask. That's why it's ridiculous that university only asked like two tribes, and even then only because the court made them. Spirit Lake said yes, Standing Rock refused to even participate. My tribe, not even being in the state, was never even asked. Nor were any of the others in my state or in any of the neighboring states.
I happen to know some who are because they don't like the stereotype. But to be frank, it doesn't matter what the Irish think when it comes to teams using Natives as their mascots. Why would it? Their opinion would only matter for mascots involving them, and if they're cool with it, then that's just fine - that's up to them.