It's not been bad per se, it's just that this team has flaws that, to win, would require either a maniac tactician, like a Guardiola, or a guru with both the ability to somehow always hit the right chords with the players and a paranornal ability to read games and make adjustments, like Zidane
Ancelotti is neither. Soon enough he'll draw the same conclusions Zidane did and revert to the ultra-controlling, slow-as-molasses style Zidane rode effectively to one title and nearly another, but I don't trust him to do as well as Zizou. In part also because Militao and Alaba are not Sergio and Varane