I think that while JJ McCarthy's play was not the best, it really was his injury history combined with some kind of friction and/or rebellious nature of McCarthy that convinced KOC to be willing to part with him. There are some Hall of Fame players with stats worse than his. His early TD dance and ballsy nature in telling the media he did it even though he was told not to by his head coach had to really annoy KOC, and that's a battle a head coach can't afford to lose. Bottomline, I think the Vikings are going to eventually regret this decision, even if it was the best option at the moment. The Vikings at one point parted ways with Rich Gannon, and look how that worked out for Gannon. I'm not sure he was the workaholic he seemed to be later in his career while with the Vikes. This may just be the wake-up call JJ needed.
And well, I have never been a Murray fan. There's a reason the Cardinals are OK with paying Murray $35.5 million to NOT play for them this year. They had already come to terms with him not being their "guy" in the long term.