hmmm... I don't think it would have been a disappointment, but that is my humble opinion. And you have a point, there was a lot of unfinished business left um.. unfinished, but regardless. I think it was a cheap shot by Kubo to continue the story any longer than that. It seems to me (I cannot stress enough that this is my opinion) that Kubo just is in it for money. Kishimoto seems to be in it for making manga. I love Kubo's art, but the story's a little dry.
And as Uriuu mentioned, neither compare to One Piece, but since this is a Bleach + Naruto group, I won't go into that here. Speaking of which, I'm going to go find a One Piece group now, I guess.