I think the point, my point at least, is that an attempt at eradication did not accomplish that. Moving people around isn't eradication.
I think it is difficult to eradicate anything, but forcing a group of people to flee a couple of thousand miles away and stay there for decades is kinda "mission accomplished" from the perspective of the people of that time. Not sure that it matters to those long dead that they came back 175 years later and built a temple in Carmel.
Not that this is a valid solution to the crime problem, of course. But you are certainly wrong about the goal being accomplished with regards to the Mormons in the early 1800s.
Also, although not "eradicated," I don't see many teepees in Carmel.