I guess thats the point, with 7% of transaction fees compared to 0-2% at online exchanges, the Bitcoin Atm isnt really interesting for experienced Bitcoiners
But for newcomers it is just much easier to adapt to a simple cash machine, similiar to the ones all people are already used to, instead of trusting unknown exchange websites and working themselves through the verification, funding and trading process, which costs a lot of time and work. So it is perfect publicity for Bitcoin, bringing new users into the system.
But I guess the flexibility and instant way of transaction of the BTC Atms is an big advantage for every user.
I believe there is 3% commision. Where have you bring that information? Anyway you are right about newcomers, it's great to them and amazing way to popularize bitcoin.