Eh, I get where you are coming from. However, you should accept it because the people with the social authority to coerce through guns or imprisonment require you to do so, instead of operating in a vacuum. Plus, land ownership makes for a much clearer system of institutions (which economists of all stripes agree are fundamental to prosperity).

Further, relaxing land ownership doesn't make current occupation an externality, which was the original claim. It's a categorical error to mix externalities with morals.