The problem is that all the companies developing Bitcoin ATMs are located in a country that will never allow such a machine to exist.
Once some companies in Asia take up the task it will probably go from drawing board to street corner in a much shortly time.
Last time I checked China was still "Communist" I dont see the chinese government allowing bitcoin ATM's as it takes money out of their own state currency.
In the United States there is no law against a bitcoin atm so its not the countries fault.
It seems like not enough people are using the ATM's then expected.