I 100% agree with your premise. I don't blame Coop for the players being bad, I blame the bad players. But it's still time Coop goes. Maybe it doesn't solve anything, but it's time to get someone in there that is willing to be flexible with the changes in the game and not so hard headed in his ways that had worked for so long.
It's the same reason you're going to see a new manager on the North Side next year. They're a good front office who will let people go when it's time, even if the failures can't be traced to that one person.