We actually don't need Bitcoin ATMs to be honest when we can do everything in online and their fees are too huge compare to the fee of an exchange so its just here for any emergency need of cash when can't execute our trade orders and withdraw money to our bank accounts.
From what I have seen in discussions elsewhere there is no KYC / AML difference for in vs out of BTC <-> fiat in most places. The lack of being able to sell BTC, or other cryptos for cash is more related to the fact that most of the ATM players are small businesses and having to keep a bunch of machines filled with cash is very time consuming and expensive. Selling BTC for cash is somewhat easier as you get an alert when the ATM is nearing full and you can go get your cash. Running out of cash to give to people causes annoyed customers.
I have 0 real experience with this as the ATMs I worked on with some people (now shutdown) were all very local to them so if they had to fill or empty it was a walk down the block or a quick 2 mile drive.
-Dave