In what way did President Jefferson have a misconception of how his plan to relocate Native American tribes would affect the native people?

U know, my friend, the benevolent plan we were pursuing here for the happiness of the aboriginal inhabitants in our vicinities. We spared nothing to keep them at peace with one another. To teach them agriculture and the rudiments of the most necessary arts, and to encourage industry by establishing among them separate property. In this way they would have been enabled to subsist and multiply on a moderate scale of landed possession. They would have mixed their blood with ours, and been amalgamated and identified with us within no distant period of time. On the commencement of our present war, we pressed on them the observance of peace and neutrality, but the interested and unprincipled policy of England has defeated all our labors for the salvation of these unfortunate people. They have seduced the greater part of the tribes within our neighborhood, to take up the hatchet against us, and the cruel massacres they have committed on the women and children of our frontiers taken by surprise, will oblige us now to pursue them to extermination, or drive them to new seats beyond our reach