You can take that situation, and use it as a case study in a HR class as what not to do. If any organization did what the Bears did, you would expect a significant drop in performance. They fired their leader that everyone on the team loved and performed for. They dissed the face of the franchise, a person with a track record of performing at a high level and the ability to make those around him better. If you're gonna do that to Urlacher, why would anyone on the team think that they wouldn't get treated the same way. If you're gonna get treated the same way, why would you go above and beyond? Even some corporate HR person with no experience with football knows better than to do what Emery did. You can't replace well respected leaders with those with less talent and charisma and expect strong morale from those that work for them.
Lovie was not a perfect coach, but he was one hell of a motivator and disciplinarian that got production out of his defensive players, even those with marginal talent. The defense went from guys flying around and swarming to the ball, to a bunch of guys doing the bare minimum. The epitome of this was a game where I saw the other team fumble in the end zone, while defenders near by just stood around until the other team recovered it. I remember saying to myself, "This would have never happened under Lovie". Urlacher was certainly in decline, but it had been that way for a few seasons. Where he didn't decline was in his ability to fire up the D and make the calls at the LOS. I believe a big part of the reason why the defense declined so rapidly was because #54 wasn't there to make the reads and calls.
The Bears replaced Lovie and Urlacher with the TPS reports guy from office space and his bumbling lackey. Why would anyone expect performance to improve in that situation. Tucker should have been fired after the NE game where the defense couldn't do anything to stop the Pats, and definitely after the GB game where they hung over 50 on us after we had a bye week. There was not enough accountability under Trestman, and the players knew that. As in any situation, when there is no accountability, nobody gives a shit.