Usually this kind of thing happens when non-salaried management is thin. Supervisors will hit a point where if they work a minute too long the store will be fined thousands of dollars by the state for labor law infraction. It's extremely unfortunate, yes. But it's more of a practical reality than it is rude or lazy. And no amount of explaining the moment to customers will make them happy.
I always give them the benefit of the doubt they don't make much.
They are having a hard time keeping the business staffed I'm sure. When I worked fast food that was always wrong as long as people are orderin you stay open.
Thanks! Your answer is awaiting moderation.