If anything, we have held on to coaches for too long. We have settled for mediocrity when it is obvious a move needs to be made. Keeping Arnett at this point, is only delaying the inevitable. If there are 5+ coaches in the conference that would take over your current coach there is no way to expect to compete going forward. With Texas and OK coming in, the path gets harder, and we can't afford to keep kicking the can down the road.
It really comes down to whether or not we want to actually compete, or if we are content with just making a bowl (non NY6 bowl). Anything outside of a NY6 bowl is essentially insignificant and does not move the needle when it comes to recruits. As it stands right now, Arnett is not the guy. I agree that at 6 wins he is 100% safe for next year, but his ceiling remains lower than more than half of the conference (KY, AU, FL, OM, SC, not to mention the blue bloods that we have to face). With the speed/climate of cfb changing so quickly, we are only going to get further behind if we do not commit to competing right now.