Barry Svrluga was just on MLB Network, and was asked why the Nats weren't able to get the FA they were after. He told them straight up that it has nothing to do with any notion of "clubhouse toxicity",
On the Nat (MLB) message board a poster summarized what Svrluga said as follows:
1- "it isn't just a toxic clubhouse"
2- Some of the "star" players are challenging
3- To many deferred payment contracts making them less valuable than the face value
4- A real cash issue since the Nationals receive less than they feel they should from their deal with MASN
5- Players declaring "where is my ring" before the season.
I don't know how accurate that summary is, but it doesn't sound like "nothing to do with"; more like "that's part of it but not the whole reason".