Listen. We can sit here before the season starts and compare the 2015 team to the 2013 team. Certainly the 2012 and 2014 teams were similar so why shouldn't we be worried that 2015 would match the disappointment of 2013? Or maybe we shouldn't be worried because... well because whatever. It doesn't matter. It's pre-season baseball filler time where we get to talk about nonsense like this. Could the 2015 Nats be the 2013 Nats redux? Sure! Could they be the best team ever? Sure! Whatever floats your conversational boats.
What we can't argue about though is the reason 2013 ended in failure. Sure, you can say it was because they were "complacent" or whatever nonsense you want and you know what? No one can prove you wrong. There's no there there. Good for you and your unassailable argument from the top of Mt. Nonsense.
I'll point out that a mere two years later and its likely not a single bench player for that team will be on a major league roster. (Suzuki will but he was not a bench guy as much as a Ramos injury replacement. Espinosa likely will but he wasn't a bench player - he was a starter usurped by Rendon - who was also not a bench player) I don't know if it was historically bad but it was the worst bench in the majors that year and cost the Nats several games. The Nats also had a bunch of injuries and saw Dan Haren, a one-year FA pick-up looking for a deal after 2013 not a 2012 Nats with a reason to be complacent, pitch poorly. This is my argument, but sure, you can say fairies might have caused them to lose in 2013, too. You're wrong but you can say it.
Why do some default to the "they just didn't care enough" for the reason the Nats didn't win in 2013 (or "cared too much" - depending on which psychobabble you like more)? Because it gives the Nats a stronger measure of control over success. 2013 was derailed by the unexpected. Injury and unpredicted poor play led to heavy use of a bench that was overly reliant on what turned out to be 2012 career performances. Outside of Rizzo fiddling while the season burned (a glaring mark on an otherwise stellar tenure) there wasn't much the Nats could do. Be healthier? Play more amazing like last year? We don't like it that a team, even this one in 2015, can be derailed by the unexpected. So poof! Let's pretend they weren't! Instead they were derailed by their on hubris or nerves or something that we can imagine that THIS time they'll be able to control better. Matt Williams will show them how. Or maybe it will be their experience from last time. Or the fact, as Boz notes, a lot of them are looking to prove something. For some, it's a lot nicer feeling than relying on the cosmic uncertainty of "Hope nothing goes crazy".
The Nats should win. They should win a lot of games in fact. But they could lose. It could happen. The chances aren't good but they exist. And just like in 2013, if they do lose, it won't be because of focus or drive or whatever (it would probably be because of injury) even if people say that's what it is.