in present time as bitcoin is not yet so much introduced in the people and its users are also not so therefore i think itis not too much worth to use bitcoin ATM.
bitcoin will be well known and it's matter about the time,a bitcoin ATM could also help the bitcoin to introduce itself to people who just curious when seeing this ATM,so a bitcoin ATM is actually worth it,and also bitcoin ATM is not about how much people who use it but how the atm could make bitcoin users feel simple when using bitcoin