About the statement from the opening paragraph: "as if libertarians object to the state enforcing property rights" - why do libertarians accept state monopoly over the property rights industry, but disapprove of other state industries? If the basis of libertarianism is a moral one (such as the oft-cited non-aggression principle), isn't this an outright moral failing on the part of libertarians? Shouldn't they disapprove of all infringements upon property rights (taxation)?
It's a broad label, one used by people who hold a variety of beliefs. You might find the "anarcho-capitalist" position more consistent, as it advocates the complete elimination of the state. Minarchism is a more moderate view, which acknowledges a need for a minimal "night watchman" state to provide services like enforcement of property rights.
One could say that stealing half of someone's money is the moderate position (in comparison to stealing their whole wallet) but I was led to believe libertarianism is based on a fundamental moral belief. Inconsistent is a nice, polite word for this, I guess.