Lol, seriously?
Sakura is a representative of the 21st century shallow bimbo that goes for the asshоle based on some loosely defined form of "love" and tolerates all form of abuse. Throw in the fact that she's indecisive as hell, has put her friends at risk all for the sake of that guy, is generally not that useful, isn't well written or entertaining to watch in the slightest, and... yeah, it's pretty easy not to like her, simply because she's a trash character.
Sasuke, on the other hand, throughout the whole time was driven by goals many readers can agree with and justify what he was doing. Wasn't chasing a girl all this time because of a non-existent good reason for falling in love, so you know - he wasn't one-dimensional. Now throw in the fact that he knows what he has to do and does it, is a strong badass, and is by far one of the best characters in the series, plus the funny fact that almost killing an annoyance like Sakura was poetic justice and also won him fans makes him completely incomparable to her.
Polar opposites, really.