Oh look! Another simplistic analysis of the world in terms of "the good guys and the bad guys", "the white hats and the black hats", "absolute virtue and absolute evil", avoiding the messy complexity of reality.

I thought that was supposed to be a nasty mental habit of white, Christian Europeans? Apparently that is something you "caught", in residential schools no doubt?

Different people no doubt had different intentions, or a mixture of various intentions. People in 1800 didn't think like late 20th century people, obviously. Some wanted to "save their souls", others wanted the land, still others wanted to provide  an education that would make it possible to function in an agricultural but industrializing world, and that meant "destroying the Indian in the child" as much as getting illiterate peasants educated meant to "kill the superstitious, ignorant peasant in the child."