Because as an audience, we’ve seen Chuck put so much unnecessary blame and responsibility on Jimmy, who hasn’t always been aware of the grudge that had been building since childhood.
At this point in Better Call Saul’s run, Chuck and Jimmy have reached several points of no return in both their personal and a professional relationships.
So we don’t even have to feel all that bad whenever Jimmy puts Chuck in his mentally eccentric place.
And as intriguing and delicate as the incredible Michael McKean is with the role, it’s almost impossible NOT to hate Chuck, even while genuine sympathy is floating around.