its as pein explained to naruto, no two people will necessarily agree on the same type of "justice". you can apply that to this situation, naruto didnt have love growing up so he wouldnt understand sasuke's pain. sasuke did have love and parents at one point, so he could never understand naruto's pain. Sakura has had love her whole life, so though she tries she can never understand naruto and sasukes pain and rivalry. the point is though, at least naruto and sakura have tried to understand sasuke's pain and sympathize with him (naruto moreso lately) but sasuke wont listen to their side or try to sympathize why itachi did what he did or why naruto wont give up on him as a friend. if you really get into the depth in which kishi is trying to express these "bonds" between team 7 and other characters, its really deep. its refreshing to see someone who actually would go so far to help his friend. not many people would do that in todays world, most would have dropped sasuke as a nutcase long ago rather than try to help him like naruto.