I am reminded of the old comedy routine about the hungry people that lived in the desert.
The reason you can’t grow food is that you live in a place where you CAN’T grow anything. Move.
Been out there trying to do some work. Not very friendly folks. No desire to go back there.
Considering that the land that the Indians have left is in most cases the worst farmland in the west that they were forced on to, that's a pretty absurd demand.
Problem is they can't and won't, not only for cultural reasons, but because of the very treaties they signed with the U.S. government. It's their land, legally, and they are not about to give it up any time soon, even though it is a desert wasteland. Indians don't think like non-Indians. Land is everything to them, even when it has no obvious use to outsiders.