Why you think Kishimoto continue making Naruto and Sakura obsessed to get Sasuke back after all these things?

well first of all, the whole plot in Naruto: Shippuuden is to stop akatsuki and get sasuke back.. thats the whole idea of the sequel!!!! and like some others said, sasuke is the most hurt, sakura has her parents, naruto never met his but sasuke met them, loved them, and saw their dead bodies slaughtered in front of his eyes!!!!! noone can undergo that and not change.... sasuke also is not loyal to the Akatsuki, he even mentioned to Madara on his way to konoha after the battle with kirabii that ''what do you want, Hebi has no longer any affiliations with akatsuki'', sasuke only wants to avenge his clan, would'nt you if you undergo what sasuke did. would'nt you leave your friends at a chance for revenge????? every other person would!!!!!!!!