Originally Posted by
Rater202
"Hey, all of those grudges resulted in us having to fight a War against not one bu t tworidiulously powerful mad-men who were driven insane by the constant cycle of war and vengence. Lets change our ways."
"Okay, but first, lets take horrific revenge on this guy who did things that we ourselves are all guilty of ebcuase we're mad at him, never mind that he helped save the world, has started to reform, and that killing him would alienate the guy that we're all friends with."
You see how that doesn't work?
As for Sasuke never reforming... The very last thing that happens before the epilog is Sasuke realizing that he was wrong and going off to make a genuine effort to atone.
Basically, the ending of the series is to Sasuke what the ending of the Invasion Arc was to Gaara--the realization that he's wrong and the first step towards reforming.