1. We've been waiting for 6 decades for a dominating, aggressive defense and Horton has finally delivered it (& I doubt anyone else would have pulled it off). I'm terrified that, if he left the Cards, our defense would immediately begin to go south.
2. I'm not sold on the "he has nowhere else to go" argument. Unless he was promoted to Assistant HC, I may be wrong but I believe another team could make a move for him by offering that title and, by matching it, the Cardinals could not automatically prevent him from leaving
3. Teams take on the personalities of their HC. Ray has an aggressive "take no prisoners" swagger about him that, I believe would become the personna of the entire team.
4. By keeping Horton, at least we know we can compete from a strong defensive base (in case it takes time to straighten out the offense). Let Horton leave and we could wind up with nothing from nothing.
Finally, I don't think magical coaching personalities grow on trees. I believe Horton has the magic.