Football Coaches and Broadcasters

I don't understand why some football coaches choose to leave coaching for broadcasting. Nothing against broadcasting, but to me, if you're a football coach, that's what you do, what you were meant to do, is coach football. Tony Dungy, Brian Billick, Jimmy Johnson, Jon Gruden, Bill Cowher... all of these men have won Super Bowls but yet are staying put as broadcasters... why do that if you were a successful coach?

I can understand if a coach wants to take a year or so off, to be with his family and take a break. I know people probably would say broadcasting is a hell of a lot easier than coaching, and it probably is. But like I said, you're a football coach, why are you broadcasting?