From my experience, if you're running a business you should be catering to what your customers want so you can keep them wanting to return for more, correct? If you have frustrated customers they start becoming irate and many times consider never coming back to your establishment again. Where I worked this didn't seem to be the case because people would keep returning even though they would obviously come in, become irritated, and then many times leave. The food must have been drugged or something. One of the main reasons they would become irritated though is. . .
Ironically one day when I worked at the restaurant the owner would work in I told him customers that would step into the other shop would become mad and irritated because we were always out of supplies or because it was under staffed. He said that wasn't true and that it was fine. Soon after saying this two customers walked into the store we were working at. I made their meals and when they were done they expressed their gratitude for it being so good compared to any other sub shop they had been to from the same franchise. Of course the owner mentioned his other store that I usually worked at, to which the couple replied, "Is that the one by the mall? Everyone there always seems angry and they're always out of stuff!" I looked at the owner and he said they probably just got somebody who was in a bad mood that day. That's fine, stay in your oblivious mental state.