The Native Americans have made an enormous mistake by staying on the reservations. The European-Americans made their own painful transition from an agricultural to an industrial and urban economy. This has been very painful for the rural areas that have lost population and whole towns as fewer farmers are needed. By staying on the reservations, the Native Americans place themselves in an economically untenable position - there's not enough work in those rural areas and never will be.
Why wouldn't the land look empty to the Indian agriculturalists as well?
That is the main problem with your Thesis.
"Most of your post doesn't make much sense."
Sorry. But some of the ancillary stuff that might have confused you is just too much work to explain properly.