He is right though, compared to other fan bases we do seem to lack energy, at least in the regular season. In the playoffs Nats Park is always rocking though. But this is an event down with a largely fairweather fan base, you just aren't going to have fans rocking during home regular season games against the likes of the Reds an Brewers.
I mean, were Royals fans rocking before 2014? Wrigley was a mausoleum until recently as well. List goes on and on. You win, and the fans will rock.