That's a rationalization if I ever heard one - finding a fake reason for something that occurred. I'd have to see some evidence on that to believe it. I know Boswell has been critical of the Nats, but players lacking desire is another matter.
I'm not saying they lack desire (although if last night was the first baseball game I ever saw I would think that). They lack grit. They don't collectively bear down and raise their level when the situation demands it. Talent - yes. Grit - no. That is a formula for regular season success and playoff failure.
Tim Hudson for SF called us out before the 2014 series, saying we had nothing between our legs, then they went out beat us. Two years earlier they sat on the tarmac ready to depart for Washington to play us in the 2012 NLCS, only to see us blow a 6-0 lead, and then get diverted to St. Louis. The pictures of them on the plane are all you need to see. The Cardinals and Giants have always viewed us as full of ourselves considering we have never won a playoff series. The Cubs totally emasculated Ryan Zimmerman by walking Bryce Harper 16 times in a May series in Chicago - a successful strategy that also seemed to throw Bryce into a tailspin.