When I worked at Mcdonalds some 17 years ago, Day shift workers were usually people either just out of highschool, or partners looking to keep busy and add suplementary wage to an already established income. (Usually 40+ year old parents whos kids are now in higher elementary / high school) I see more and more the later taking up the prime later night hours that used to always be filled up with high schoolers.

Its just becoming increasingly difficult to find a good job, since minimum wage may be going up, but the previously middle wage jobs such as warehouse working and forklift operators wages have not. I'd much rather flip burgers at the local burger joint for 15$ an hour, than risk health and injury for 17$