-Gaara is now kazekage who sacrificed himself to save the village, while sasuke only sacrificed himself for his friends
-Naruto TnJ'd gaara but couldn't do it to sasuke
-Gaara had the same childhood experience as the main character naruto, while sasuke had a completely different childhood experience
-Gaara is loyal to the village while sasuke for the majority of his life has not been
-Gaara's attitude is "better" than sasuke's
-Gaara cares about what the people think (kage), sasuke does not
I have missed something, if so note it. All these reasons can be argued depending on what people's perspectives of what is deserving of hate, or not, is. Doesn't matter what some people do, there will always be others that hate them regardless of whether they seem good or evil one person's or majority's standards.