Why? He was nuts in an entertaining way and was one of maybe 8 or 9 guys on the 2009 team who had any business being on a major league roster.
Towards remembering why some might’ve booed:
https://www.si.com/mlb/2010/09/03/code“Virtually all of it was grounded in the Code. A quick timeline:
Aug. 25: Morgan allegedly throws a ball at a fan in Philadelphia. The relevant unwritten rule -- somewhat unique, in that it has more to do with players' self-preservation than general respect -- says that ballplayers should never engage with hecklers because it rarely ends well.
In this case, the league quickly levied a seven-game suspension. Morgan, claiming a misunderstanding, has appealed the decision, and at least one fan has corroborated his account of throwing a ball to a fan, not at a fan.
Aug. 27: Morgan gets picked off first in the eighth inning of a close game against St. Louis, which proves particularly costly when the batter, Willie Harris, subsequently hits a home run. The Nationals lose, 4-2. Morgan is confronted after the game by Nationals manager Jim Riggleman, and dropped from leadoff to eighth in the batting order the following day.
Aug. 28: Morgan tries to level Cardinals catcher Bryan Anderson in a play at the plate, despite the fact that Anderson has his back to the play and is moving in the opposite direction. This means that Morgan's desire to take out the catcher draws him away from the plate; he's ruled ineligible to score when teammate Ivan Rodriguez spins him around near the edge of the cutout to go back and touch safely.
There are two sections of the Code at play here. One says that a runner should only try to take out a catcher when the plate is blocked so sufficiently that a slide would likely lead to an out. Even more importantly is the rule that says to never let personal vendettas get in the way of the team's success. In this case, Morgan's circuitous rout away from the plate was all about inciting violence -- Riggleman posited that Morgan was angry about his demotion, and took it out in any way he could -- and not at all about adding to his team's run total.
Riggleman was angry enough to call his player out in public, after apologizing to both Anderson and Cardinals manager Tony La Russa. Morgan did an "unprofessional thing," he told the media, and, indicating that lessons will be learned, said that "You'll never see it again." (In this regard, the manager was incorrect.)
He then benched Morgan for the series finale, under the auspices that the outfielder had become too prominent a target for the Cardinals to safely take the field.
Aug. 30: Morgan responds to Riggleman. "I guess he perceived it as some nasty play with the intentions of trying to hurt somebody before coming to me and asking me about the situation, which was very unacceptable," he tells The Washington Post. "But on my half, I'm not going to go ahead and throw fuel on the fire. I'm going to try to be as professional as I can about the situation."
It's frequently the case, of course, that whenever players feel the need to delineate the fact that they're being "professional," they're actually being anything but. (Code violation: Never call out your manager in public.)
Morgan, in fact, cited the unwritten rules in his own defense, saying that Riggleman "just basically did a cardinal sin. You don't blast your player in the papers." Unless, of course, his behavior has deteriorated to the point where the manager feels he has few other options.
Aug. 31: It doesn't take long to stir up more controversy. In the 10th inning of a scoreless game, Morgan runs into Marlins catcher Brett Hayeswith such force that Hayes is later shelved for the remainder of the season with an injured shoulder.
Unlike his last collision at the plate, Morgan did not go out of his way to reach his target, but consensus held that he would have been safe -- with the go-ahead run, no less -- had he slid. (See previous Code citation about running into catchers. The Marlins then won with a run in the bottom of the frame.)
When he took the field for the bottom of the inning, Morgan again got into it with fans, this time being caught on tape cussing them out. (See previous citation regarding fan interactions.)”