She is deeply in love with Sasuke even after he tryed to kill her a couple of times.
Sakura thought he was perfect back in early part 1
Then after he got the curse mark and more further into part 1 she developed more feelings beyond just infatuation for him and found out he wasn't exactly perfect and had flaws in his character and wants to help him no matter what just like Naruto
Maybe Kishimoto was dumped by a girl who liked bad boys, so he created Sakura and her love for Sasuke as a social criticism of women who can't help but fall for the same *******s who don't treat them right.
she has the emotions of a little child who can't see whats in front of herself, and she is Schizophrenic since she has chi bi version from what I remember during the academy arc.
it's like how you like that special someone. no matter what they do, you still have a special place for them in your heart bro. It's stupid but it happens.