That's a straw man so obvious, it almost self-labels as a strawman. "When libertarians say they want a free market, they aren't actually saying they want a free market..." Come on, if you have to stoop that far, when you're deliberately and openly rewriting the terms that somebody else is using, why not just admit you don't actually have an argument?
What rewriting? "Night-watchman state" and "necessary axioms for the Efficient Market Hypothesis to hold" are completely different things. The libertarians are making an argument from (broadly, there are several branches of libertarianism, after all) Nozickian ethics and conflating it with mainstream economics.
