I've been rereading a lot of the early Naruto arcs for research and it's notable to me how whenever Kakashi is unavailable, Sasuke is immediately stepping up to fill his role. He might have been the baby of his family, but he is older brothering this damn team.
He's accepted Kakashi as an adult who can protect him (which will be lost when Itachi takes out Kakashi) but in absence of that one trusted adult, he attempts to kill the scared boy inside so that he can take over the protective role. Because the only way he can open up his heart again is if he doesn't fail at protection this time (see his psychosis scene where his younger self berates him for "letting" his family die).
But after half a dozen tries, the end result proves that not only can he not save his precious comrades (from Orochimaru, Gaara) but he can't even save himself (from Itachi again). When he wakes up in that hospital bed, he says they shouldn't have bothered saving him, and he means it. Kakashi needed to address that more than the revenge, if he wanted to stop Sasuke's self-destructive spiral.
