Diners, in particular the old school, greasy spoon, fake-leather-booth-that-your-legs-stick-to-if-you're-wearing-shorts, tchotchke-filled, usually worn-out joints that are always staffed by harried, but nice waitresses who call you "honey" and take your orders on notepads with a pen (or memorize them), are by definition, fun.
What an unadorned coffee-holder has to do with power lines and the U.S. military.
The media hasn't been too kind to the Motor City, so most people who haven't visited seem to assume it's a wasteland of abandoned buildings and zombie workers from old car factories.