I know shorter stints but wasn't he the chosen one just last year? I could be wrong but it seems like he went from being hero to zero pretty darned quick.
This is NFL. Losing isn't accepted by most well run teams. And when some owners/GMs see poor coaching and terrible decisions out of their head coach they are out on their ass. They don't need to see it more than once (unless you are in Miami). Haley was bad this year, starting a verbal fight at midfield with Harbuagh after a preseason game was the start of his downfall. He came off as a barking mad fool.
And one thing we have learned "the injury excuse" no longer fly's in the NFL. Nobody had more injuries than Haley, still gone. Caldwell, he is going to get fired. Win games or be fired, the days of excuses are over with.