You have to deal with some of the worst people imaginable. All kinds of ignorant, uneducated, and downright stupid people. Some are rude, some smell bad, and others will flat out waste your time.
This of course, is good for the company, because then they don't have to pay you as much. While you sweat through how to deal with Billy the Hobo, you're making $4 an hour, and when he's still talking to you two hours later, you've made a grand total of $8 dollars.
The way the pay works is just laughable. They call this competitive, while they watch all of their employees quit because the pay scale is a joke. If there are no customers, or you have to open or close, you are practically working for free. They advertise good wages when you interview, but the reality is you'll just be left to slog through a dozen or two horrible people every day for less than or equal to minimum wage.
Managers will not talk to you about moving departments, even after you put in an application. They will ignore it until you bring it up in person.
Your schedule will change so often that making plans after work becomes a job in itself.