I'm gonna need a definition on what you mean by "sacrifice" and "pointless".
I agree with you on Neji, Rin and Hiruzen. Definitely. BUT.
Itachi—— died. Not sacrifice. He was a partially dead man anyway and sure let's say he "sacrificed" himself to Sasuke so he'd get the mangekyo sharingan (or whatever else it was for, like extracting Orochimaro's remains from Sasuke), then that wouldn't be pointless now, would it? There was an obvious point!
Nagato... Sigh. Pointless? The Rinne Rebirth brought Kakashi back to life... Brought several other people back to life, was a sign of Nagato's repentance and solidified Naruto as the hero of the leaf so... Again, THERE WAS A POINT. Forgetting the "faith" Jiraiya had in him was a part of his arc. That's like saying he should have remained who he was when he was a child.. Even though the story made it clear even when he was a kid that when his loved ones are threatened he had the potential to do real evil. EVEN THEN???
Deidara... Did NOT sacrifice himself. Pointless, yes. Sacrifice, definitely not.
