Probably because their terms/price sucks.
Someone on here was trying to get a group buy together for one; the contract was terrible for the buyer, basically the buyer pays for the ATM upfront, but continues to pay the vendor 50% of fees forever....so buyers put up all the capital, take all the risk, run, house and maintain the machine and only collect probably less than .5% per trade when all said and done.
Pretty much why I went with the Lama for an experiment as the risk is the same
If it passes maybe then look at the robocoin as a risk equity calculation lamas just make the best business sense when penetrating a marketplace.
https://bitcointalksearch.org/topic/open-robocoin-btc-atm-operating-services-available-in-us-and-internationally-330662
https://bitcointalksearch.org/topic/robocoin-bitcoin-atm-ownership-shares-us-purchase-and-placement-343821
Contract for Robocoin is on the two links
Robocoin ATMs Now officially cost 20,000 a unit was 18,500 in 2013 as a special offer