I think the Nats cutting Dusty Baker loose by not renewing his contract had a similar feel to Girardi. Both programs truly want to go in a different direction and one that is decidedly grounded in advanced performance metrics. Girardi had a great run with the Yankees, but I suspect it had simply run its course and it will work out for the NYY.
I always felt that Dusty was an "oh snap" pick-up in response to how horribly the Nats screwed up on Bud Black (I was excited he, briefly, looked like he'd be the Nats' manager). Dusty is rightly a legend. But I also think his "old school" ways rightly or wrongly contributed to a perception that he was not going to be the person to snap the Nats' documented post-season slump (nascent curse). I also think his keeping Jayson Werth in the line-up after his injury truly hurt the team offensively and defensively, and simply put--it could not be justified outside a light of loyalty.
As for the Nats picking up Girardi, I don't know if that will work out...but I do know if they take a pass, there will be a whole lot of 'splaining to do!.