Sasuke defecting from Konoha was the correct choice and supported by the narrative. The sound four didn't manipulate him.
I find it kind of strange, Kishimoto took such an obtuse route in how he portrays Sasuke's cause in Shippuden. Purpose and ambition were essential themes in early Naruto. Gara pretty much sums it up here:
Sasuke also feels the same way. For what reason did itachi spare him? For what reason does he exist?
Kimimaro hammers home the existential philosophy Kishimoto was conveying, that purpose is what drives people, regardless of morality or mortality.
As Kimimaro states, "Everyone has something important to accomplish. The quest to discover what that is... Is the only freedom God has given us humans."
Ambition is portrayed as life affirming. That's why Kakashi's warning that revenge would leave Sasuke empty falls flat. Tayuya is correct in how she frames this so-called camaraderie; the alternative Kakashi provided amounts to idle wound licking.
Would Sasuke really be better off in Konoha, while the man who annihilated his kin roams freely? It isn't a coincidence that both Lee and Sasuke discover the resolve to pursue their ambitions in the same time frame.
Both Lee and Sasuke are at their lowest, and directionless when their respective sensei come to guide them. In contrast to Kakashi, Gai's advice to Lee is honest; Lee would suffer more if he lost his ambition. They both acknowledged that Lee's ambition is precious enough to risk dying for. Kakashi, however, doesn't acknowledge Sasuke's ambition at all. So yes, Kakashi was objectively wrong, and vapid in hindsight.
I'm going to make a reboot or this soon
