Mal, there's been plenty of responses to this suggestion. Personally, I think Ortiz would be a horrible choice as manager. Leaving aside the fact that he's never done anything remotely like it (i.e., no experience), he's still too close to much of the team. A year ago, he was Big Papi. One of them. They aren't going to see a manager, they are going to see Big Papi. Yes, there would be enthusiasm. But there is waaaay more to the job than being head cheerleader. As somebody said earlier, there is a reason companies go outside the immediate organization for managers. It's hard to be the boss when the day before you were one of the minions.
Why would he subject himself to the fishbowl that is the Red Sox managers position?
Selfishly, I don't think I ever want to see him as a manager. He is a legend in Boston. Eventually, virtually all managers do not go out on their own terms. The ones that do have managed a long time and almost always have been fired somewhere along the way. And he would be too.