Long story short, people will always go to the games.
No, they won't. They'll watch them on TV, they'll drive the needle on sports talk radio, hell they might even buy a hat or t-shirt every one in a while. But people will not always go to the games like lemmings. It's just too god damn expensive and the in-stadium product is just not worth it. Unless you love getting blackout drunk and acting like an asshole.
As much as I love going to Nats game, the main draw for me is exactly that. Drinking a shit load, yelling at New York/Philadelphia teams, and eating awful food.
You're not going to have a 90,000+ stadium not be 80% full because the team is awful. Redskins fans are faithful, if not the most faithful. I watched games on TV last year, i watched them all. I went to see them get their stupid assholes handed to them by the Steelers on MNF while a good half of the stadium were Shittsburgh fans. It's about pride. DC refuses to admit it's wrong hahahaha Now, 20 years? Then we might see the Skins fall off. So, what, 9 more years to go? Ovi's still here for another 9 or 10 right? Bryce Harper will only be 27 right? John Wall will be a crafty veteran? We'll see!