To add - Those types of guys are adverse to learning a new trade from the ground up and spend the required time in the minor league system plying their trade. This includes riding the buses and such. Superstars generally do not prefer to go that route.IMO, the best coaches are the guys that were grinding, run of the mill players that had to work hard to get everything they achieved, as opposed to the naturally talented guys. You can't teach natural talent. But you can teach all those things you had to work at to become a major leaguer. Gretzky was a lousy coach. Gerard Gallant got his team to the finals in his first year in Vegas.
The only star players managing I believe is Molitor and his record has been less than stellar and Mattingly, who has done a pretty good job (save for this year with the Marlins).
Hard to believe Scioscia has been managing the Angels for almost 20 years.