A truly idiotic comment. Indians on the res are better than first-class citizens, with special privileges not available to anyone else. Such as the right to ignore state taxation and gambling laws.
No Indian is required to live on the res. They can live anywhere they please, and still get some special affirmative action privileges in education, employment, etc.
You’re right. The author is Canadian, not American, but I don’t think his criticism applies there either, though I could be wrong.