What were they going to do? Flores would have been a much better option, but he saw exactly how life under Tomlin actually works and he wanted nothing to do with it.
Honestly, the defense was so bad at the end of last season "someone other than Austin" would have sufficed. At least it would have shown they weren't satisfied with the status quo.
Keeping him and expecting different results borders on insane.
Since Tomlin obviously isn't going anywhere for at least a few more years, Rooney needs to step in during the offseason and force Tomlin to yield more control of the defense to whoever the next DC is.
I am giving Kahn a limited pass on this as I believe Tomlin has the final say in everything.
It's why I wish they would have gone outside the organization to replace Colbert, like they did when they brought Colbert in from the Lions to replace Tom Donahoe.
Khan had already been working with Tomlin for too long before becoming GM.
He came into the league as a finance guy and pretty much learned everything he knows about football from Tomlin as well as Colbert.
Sometimes some influence from elsewhere is necessary when things get as stagnant as they have with the Steelers.
One could argue that is what they did with Andy Weidl from the Eagles, but he has no real authority in the organization though.
He's still basically just a head of scouting, but with a fancier title and bigger paycheck than what he had with the Eagles.