In a story that has made a central theme of the notion that no one is ever irredeemable, how does that explanation sit right with you? I'm not saying that there aren't ways to explain why Naruto said what he did. Kishimoto can pull any explanation he wants out of his ass and set it all up to coincide. I'm just pointing out how lame the explanation is when compared to the theme that's been shoved down our throats from the beginning. Especially when this is basically what transpired in this chapter:
Naruto: "No offense Sage but I felt like your mom was an irredeemable bitch, unlike my awesome mom."
Sage: "None taken, I feel the same way about Sasuke."
Naruto: "Fuck you, Sage. I'll prove that even someone like him can be redeemed!"
Talk about convenient inconsistency...
I'm fine with it because I couldn't care less about Kaguya, and I don't think we were really meant to since she was dealt with so quickly. She was a stopgap villain, if you could even call her that, and it's actually a refreshing change of pace to see Naruto go, "No, that bitch was too much crazy" rather than go through the effort of trying to talk sense into a creature that has none.
I'm actually hoping that Naruto comes to the same realisation with Sasuke. Naruto already tried to talk to Sasuke, he's already tried to help him, and every time they meet Sasuke has become more evil, so now I don't want to see Sasuke redeemed, and I don't want to see a long, drawn out fight. I want to see a good, one-sided ass whooping that ends with Sasuke either dead or exiled. No hugs, no bromance, no heart to hearth, just a fuck you and a fist in the teeth to go with it.