IMHO:
- The Nats have gone out of their way to be "DC's team". With the Orioles having a 30 year head start, they seem to be uninterested in marketing to people even in the inner suburbs. Just inside the city limits. If you look at the dynamic of DC, the middle class and upper middle class live in the suburbs, the ultra rich and the poor live in DC. Rich people go to the opera, poor people don't have MASN, and aren't what advertizers want anyway. People in suburban Maryland, and even suburban Virginia (the place the stadium should have been built) are made to feel unwelcome.
- Further, they have done nothing to claim the regional market, such as the rest of Virginia, eastern North Carolina and the Potomac highlands of West Virginia.
- DC is made up of a very high %age of people from elsewhere. Many from the northeast, with loyalties to "their" teams.
- There are "baseball towns" (Cincy, St. Louis, Kansas City, etc) and "football towns" (Pittsburgh, Cleveland, etc). Washington is a football town.
- The team stinks.