D.C. was a bad idea.

That just about sums up everything that is wrong with it. Instead of putting the capital in a real city, the Founders decided to stick in a place where there was absolutely nothing. Try to socialize organically in D.C.: it won't happen. Few of the people who work there live there, and even fewer of the people who live there have work. The result is a so-called "city" without actual hangouts like cafes, decent bars, or cheap eats. Instead, you have a place with unaffordable hotels and boring convention centers.

The words of the traveler Jean-Jacques Ampère, who was there in 1851, pretty much sum it up: D.C. is "striking proof of this truth, that one cannot create a great city at will."

(Oops, I first posted this as a comment ... )