I agree with all but your first sentence. Perhaps I am projecting my own beliefs on nickff, but nowhere did they say that government should not provide police or similar services. They correctly stated that the private sector has the substantial advantage of being able to fail if they do a bad job. The obvious conclusion is that Government should not do things unless there is a compelling reason not to leave it to the private sector. As you point out there is a reason for the government to provide police (and other services) that outweighs the private sector's fundamental advantage.