Bill Belichick's history of "fixing" malcontents is highly over-rated. Although I credit him for being a phenomenal coach—the best in the league—the way he is portrayed as a draft genius and for his rehabilitation of "problem" players is sickeningly inaccurate.
The malcontent nature of Corey Dillon was highly exaggerated. Dillon was nowhere near the reformation project that he was made out to be. He was simply tired of playing for the Bengals and their apathetic approach towards competing. Dillon was not the first and obviously not the last. Chad Johnson tried to get out, and Carson Palmer chose to retire rather than play for them any longer.
Moss came to the Patriots on the very cheap from the Raiders, perhaps the only team in the league with the same level of ineptitude as the Bengals. He had a reputation for only playing hard when he was having the ball thrown to him—A LOT.
Perhaps that is the reason why the 2007 Patriots set the record in points. They consistently ran the score up on teams, when the game was already decided.
The record of TD receptions Moss had in 2007 was accomplished because the Patriots would continue to throw the ball late in games, when most teams generally try to run out the clock to avoid potential injuries—and end the game quicker.
But the Patriots wanted to keep Moss "happy." Unless he was catching passes, he was not an asset. He won't block for the running game or run hard routes to free up areas when not the primary receiver.
It didn't take Moss long to revert to old habits of only contributing when "he got his." The reality is that Moss simply played at his normal level—both the positive and the negative—as he did in Minnesota after a few down years.
Now it's Haynesworth who is the latest diva. The reality about Haynesworth is that his reputation is as a selfish player that plays hard—but only when it is good for him.
The Patriots team that he is joining does not have a strong structure of proven veterans who have earned respect in the league. There is no Mike Vrabel, Teddy Bruschi, Richard Seymour, Junior Seau or Rodney Harrison in that locker room.
If you are expecting a self-serving and highly egotistical Haynesworth to automatically fall into line, when the defense around him is full of young players who weren't exactly that good last year (25th in the league in yards), you're deluding yourself.
To be fair/honest, Haynesworth will likely do pretty good this year and may even return to Pro Bowl level. But do not expect him to be a long-term solution and morph into a great teammate and locker room leader—or make the Patriots D elite.
Tigers don't change their stripes. This guy has done multiple wrongs and has never learned to make himself better from any of these previous experiences. That is not going to magically change simply because Bill Belichick is coaching.
The Patriots would have been better off keeping Richard Seymour, instead of trading him for a #1 pick that won't reach his potential until after Brady is retired. And they are still going to have to address the contract issue—maybe not this year based on the conditions of the trade—but after the season. The Patriots have also made a lot of players frustrated and outright angry by low-balling them, and Haynesworth will magnify those problems to the 100th degree.
Any benefits from this trade will be short lived and the consequences will over-weigh them in the end. This is what happens when a team is run by one person rather than a collaborative effort, like when Pioli was in New England.