I could definitely use more variety in the patrons' appearances. Why else would the player be concerned what color people are sitting where? There are six types of customers, each with their own behaviors: senior citizens aren't impatient but they're not great tippers, for instance.
So, basically, Diner Dash is an exercise in segregation. Customers are color coordinated and you'll earn more tips if you continually seat people of the same color in the same seats. What could be more ordinary than waiting tables? But there is a part of the design that doesn't make a bit of sense. Whereas many videogames indulge our fantasies by giving us supernatural powers or allowing us to explore other dimensions, Diner Dash is planted right in the middle of our reality.
