Last I checked... Ron Paul was a Constitutionalist, not a pure Libertarian. This is an end-goal which will never be accomplished, the Libertarian platform. If you look at how banks work NOW, you'd probably reconsider "letting banks do their thing." The government works FOR them (see Federal Reserve Act).
It's not difficult to understand basic monetary policy... especially the printing of money. It doesn't work in the long-term... The best argument I have; we've had 100 years of big-government Presidents, what harm can 4 years under a Libertarian do?