This actually made me curious to know what data exists about the perceptions of the offensiveness of the name. So for what it's worth, Berkeley did a survey this year, and they found that, among all of those who self-identified as Native American, 49% "strongly agreed" or "agreed" (7-point scale) that the Redskins name is offensive, and the percentage is 67% among those who were heavily-engaged in their tribal cultures.
https://news.berkeley.edu/2020/02/04...ascots-survey/
So it seems it's definitely not unanimous, but it's also not a tiny portion who find it offensive.