1) Profit margin is likely 5-10% because 1) it's a food-service business, a type of business that is known for low profit-margins do to a long list of unavoidable expenses and high overhead cost and 2) they aren't being run as efficiently as possible (aka sloppily). Sure, it could be improved, but that's irrelevant to the context of the issue I'm raising.
Are you not reading what I've been telling you? And regarding irrelevancy, well, let's just say it's not irrelevant as soon as you decided to start bitching about the workers because you had a bad day.