It's the manager's job to manage the players. Things got so out of control with Morgan that Mike Rizzo had to get rid of him. That didn't happen in Pittsburgh and it obviously hasn't happened in Milwaukee.
Is Morgan insane? Sure. But he has ability. The Nationals would have been a better team with him in 2011. Good managers/coaches get the best out of guys like this. If Phil Jackson could get hall of fame performances from Dennis Rodman, then Jim Riggleman should have been able to keep things from completely spinning out of control with Nyjer Morgan.