1. Terrible, lazy defender. Routinely out of place and routinely burned. Last two games alone, Sullinger and Nene/Gortat have punked him on both ends.
2. Bad teammate. Routinely blames his teammates for his OWN mistakes. Just tonight, he was heard loud and clear cursing out Carl Landry in front of everyone on the court. You just don't show such disrespect like that to your teammates when you, yourself, are a lazy, hypocritical numb nuts. He freezes out players he doesn't like and defers to his best little friends on the team.
3. This may be the most important and direct reason...he's a loser. He puts up empty stats on one of the worse teams in this league. How many times is the game well out of hand, yet Cousins is still in there padding those stats? NIGHTLY. Cousins will make damn sure that box score is impressive, no matter how meaningless it is.