The problem using Bitcoin ATM's in my opinion:

1. The high fees
2. The need to wait (until the transaction get confirmations) and you receive an SMS to withdraw the money - Hopefully this gets solved with LN in the future.
3. Asking for passport (ATMs have cameras) after certain limit. Probably due to regulations but still...

Aside from that, they're really handy and the companies behind them (in my case Bitaccess) are very helpful and have a fast support. I had a transaction where things went wrong, I contacted them and they refunded me.