Joe that was my first thought. after going through automotive school, it took a week worth of training every semester in every class to go over the tools & safety information and pass a safety test, and then you still had to sign a waver in order to work in the shop. It was a PITA each semester, but we never had any injuries.
It doesn't seem safe having prople just drive in and start lifting cars. maybe if there was a tech in each bay and he was the one lifting the car... but if you are paying for a tech in each bay why not just have him do the work... if you are getting techs just to sit there and operate the lift, what kind of techs are you hiring, they can't be worth their salt.
I do like the Idea, maybe if it were the 50s and people weren't suing over hot coffee