If I may defend him for a moment. I haven't heard anything he has said, but maybe once he decided he was going to retire, he didn't think he would give the team his all. He wouldn't have skin in the game, his mind would be elsewhere. I bet that he knew that upon making the decision, he might as well do it immediately instead of playing out the string as a lame duck. That, and it avoids attention should he announce his retirement but stick around, as then the second half of the season would become all about him and his legacy instead of the team. To an extent, that's going to happen this way, too, but less so since he won't be on the sideline and there won't be some countdown to his last game.