>>283259290
As a professional SasuSaku hater I've thought about this a lot more than Kishimoto ever had and it could only really be explained believably like this:
From the academy days Sakura could see Sasuke's potential and the inevitable prestigious ninja career that would come of his hard work. Sasuke deviating from this path makes Sakura feel personally responsible to intervene on his behalf, but Sasuke is a train wreck that she can only watch. Her dad probably told her to get over that Sasuke kid which reinforced her resolve.
Instead of logically moving on she feels more deeply responsible for salvaging a situation that she drew herself into further with the confession which is how she ended up trying to find resolve to kill him with a poisoned kunai to at least keep Sasuke from dishonoring himself further.
Sakura putting on a brave face during the war knowing nothing has changed culminating in her desperate appeal, which she knows is futile given he was going to let her die in lava minutes before but the fact he used his rinnegan powers to switch places with her flak jacket instead of her means he isn't completely gone.