There's a Harvard Business Review case study about Taco Bell; they didn't start being financially successful until they realized that they're not really a restaurant. Since cooking food isn't their core competency, they shouldn't compete and compare themselves with real restaurants. What they do best is make economical, pre-portioned, cafeteria-style food items that only need to be warmed up for serving.
If that doesn't tell you all you need to know about Taco Bell, well, then I don't know what else to say.