Here's the thing, Brandon. You're making an assumption. You have no way of actually knowing that until you try another DC. How many times have you seen new defensive coordinators go to a team and turn them around in 1 or 2 seasons with mostly the same players? The actual evidence points to the problem being far more related to scheme than talent. Just in the last 2 years, Hayward has gone and become a stud. Hyde was decent here, but is a stud elsewhere. Peppers appeared to be declining, but he's back to his old self in Carolina. Capers is predictable. He's a fan of playing soft zones. He doesn't like to jam receivers. His blitzes are poorly timed and schemed. He's awful.
When you bring in a new GM, he usually wants his own HC. What you are talking about is re-building. This team doesn't need re-built. It needs tweaked, particularly on the defensive side. Replacing Capers is the first step to that process and it may very well be the only one necessary. Consider this: Rodgers has been with MM his entire career. They compliment each other. He's up for an extension very soon. That's an apple cart you do NOT want to upset. I doubt Rodgers wants to be part of a re-building project at this point.
When you boil this down, you seem to think we should be Super Bowl contenders without Rodgers, and since we're not, you want to nuke the whole thing. It just doesn't add up in any way.