The way it is worth is veteran leadership. I think he helped but you can't quantify it. So some here will dismiss. Not his fault Drew Storen couldn't get an out.
The Werth signing did provide hope to hungry fans and signal that the team was ready to get serious about building a roster that could win. That symbolic value , along with veteran leadership, are what fans often cite when discussing his value to the team. But did he really lead or provide an example in a way that especially helped the Nats? We can’t know for sure if the example he provided, vs what could have been provided by other vets, was particularly positive. I always wondered whether his sullen A-hole persona might actually have been unhelpful. I’m not saying that signing him was a mistake, just that I think many Nats fans overrate him as a player because of his distinct look and the symbolism associated with his acquisition.