Lol. And he doesn't even "compete" to be good at commentating.
For me personally, if I am not competing for something, anything, life is boring. If I am not involved in some investment, business, game, sport, even coaching my kids teams ... it's the closest think to primal energy we have in this society of being in the Jungle and BEING ALIVE. Sure there is a time to step back when you get burnt out, but the longer you are away it builds up inside you. I can understand why some people don't get it. Its not a feeling everyone shares, but to have another shot at coaching at the highest level and proving yourself with results sounds infinitely more exciting to me than watching and commentating. I would choose to coach again if given the right opp, but that's just me. He's already made more money than he needs to outlast his life. Nobody is going to say at his eulogy, and this man made $XX number of dollars over his lifetime, making wise decisions to commentate for more money over coaching. But if he gets another ring, or two, or three ...
Once you have enough money, you don't really dwell on making more of it like when you did when you didn't have it and are trying to make it, unless you have a love for making money (which is the root of all evil). It's just a different mindset. Look up Maslow's pyramid & hierarchy of motives & needs to get an understanding about how rich people think compared to poor, middle class, etc.
http://www.simplypsychology.org/maslow.html I know its a theory, but I have found it to be true over the course of my life. He want's to realize his full potential, and that might not mean coaching football again, or it might. Only he knows if he has the bug to come back or not. Maybe he wants to be the best racecar driver. I don't know, just saying that is why coaches come back after a hiatus. Notice the highest order of the list of that link "Transcendence needs - helping others to achieve self actualization." I can tell you from experience in coaching, this is one of the most satisfying feelings in the world, helping kids achieve greatness. Its a personal great feeling when you help another. This is why coaching is so rewarding. I feel even better about teaching/coaching kids and watching them perform not just as athletes, but as young responsible men than I do about my own achievements. Gruden is not feeding this need as a commentator. You have to be on the field, coaching to fulfill this need.
He gets only so many years to compete. Added incentive ... I always like to compete with my brothers. We are about to meet up again this Christmas at parent's home, and each year you bet it comes up about bragging rights for our fantasy league when one of us wins, also even the week we play each other the loser gives the winner a concession congratulatory call after Monday night game LOL. Well take that a step further in real life if the Gruden's face off in real football. He never had that chance his first go around. Sounds a lot more interesting. I know the Harbaughs had a few interesting holidays.