You could argue that Indians is no different than Vikings, Celtics, or Fighting Irish, and you'd have a point. Chief Wahoo will definitely have to go, though.
I don't think it's that it's Indians. It's that they're not supposed to be called Indians. That's a term of ignorance....and one that I use, even, but I get it. If they were called the Native Americans or the Cherokees or something, it would be fine. There are ways to honor and there are ways to mock. The Indians mascot is a caricature of Native Americans, whereas I don't feel the same way about the Blackhawks mascot.
That's just me. I don't have a problem with any of this, but I don't think they're the same.