You can't run around blaming GMs whenever players manage to score big bucks somewhere and their current team just doesn't see it as an appropriate amount to pay. Another example is McCloud who got huge bucks to go to Philly.
That said: you also can't pay a guy like Foles $12mil (when you didn't have to!) and then run him out of town and eat the money.
JJ was always going to be a difficult re-up. And, he probably needed to go somewhere where winning was a real possibility. It was never going to be while Fisher was coaching the Rams. And I have no doubt that at least some players factor that into the equation.
I'm not a big Snead fan.
I don't like his "swing for the fences" mentality with 1st and 2nd round picks because it doesn't work out any more often than it does. Too much you using premium picks and paying premium money for guys who will take extra development time. Take the good player that is the most advanced (like an Aaron Donald) so you can start getting production and contribution from them early.