You are still engaging in the same kind of social transaction when you take your body out into the world. If it were a car, you would be required to insure it against accidental damage for one reason: to avoid throwing that burden onto the commonweal. Having to have a minimum level of health insurace does exactly the same thing for the meat vehicle. OTherwisde, if you have a stroke in the middle of a movie theater, a huge amount of cost is going to be levied against health care providers or public treasuries to get you taken care of, no? Where do you think that money should come from?

It is not a tax in the normal sense of the word, but if Roberts wants to call it that, fine.