Napoli-Mathis situation, Trumbo-Wells situation, bullpen/pitching change management, players do not perform to expectations under him, lack of intensity from the outsider's view, questionable bunt strategies, questionable lineups last year, lack of willingness to bench veterans, stubbornness to change, slow starts, missing the playoffs the last three years, and no leftover lasagna.
It is not just because of this year. It is a culmination of the years prior as well as another poor start this year.