Earlier quoted context omitted.
Need to make sure that restocking is done during the day or the customers won't notice that you have to move large containers through the store! I understand that most stores would see little traffic at night, but on the other hand they'd also not need full staff, and they absolutely could do all the maintenance work at night. It annoys me similarly as "everybody must have the same two days off". So inefficient.
Having the same days off for most people makes for a more cohesive society where people have more time to interact with each other. Or at least, that's the idea. Knowing families where people have different working hours or working days, it really takes a toll on interpersonal relations.
That's not our current reality, the percentage of singles and childless couples is growing and they don't need to be timed with school hours.
Adding flexibility would make everything run more smoothly. Right now we're having all the commercial traffic on 5/7 days and all the leisure time traffic on 2/7 days. Offices are empty 2/7 days.
Distributing that more evenly would benefit everyone. Less traffic during rush hour, less overrun parks on your day off, less crowded super markets and packages wouldn't need to be considered lost if they're diverted to the local branch where queues are usually longer than those in front of apple stores when new iphones get released.