At those rates, those things are starting to target one-time shoppers, fleece them as much as they can, and then to the next buyer or more like victim rather than focusing on volume and on dedicated customers. Just for fun, I looked two weeks ago at a Batm, the fees were not that bad at 7% but buying 100 euros worth of bitcoin wouldn't get me 93euros in my wallet because they would also charge me close to 15 euros for the tx.
If they keep these things up and go full KYC on every purchase they will soon be left with no customers.
As you say if they had a real interest on trying to get as much money as possible they would be focusing on getting volume, for example there are gas stations that charge you a cheaper price for the gallon of gasoline and they do this because they are expecting for their clients to notice and regain that money with the increased volume on sales they will get and the same principle would work in bitcoin ATMs and the fact they are not doing this proves they do not really care that much about the volume they will get out of their ATMs.