I believe OSHA may have other thoughts on that subject. I would remind or suggest they contact OSHA and find out what the current fines are for non-compliance. I believe they may even shut them down for not supplying safety glasses and if an injury occures...well that could also shut them down, cost hundreds of thousands of dollars, and possibly put some or all of management/owners in jail.
They also might want to check out
www.osha.gov 
Just a thought...
The normal other operations in the shop beyond enclosed and door safety switches on the CNC's will still demand the need for safety classes. The only time glasses should not be a requirement is when nothing is running.
Steve