People don't like her because of her hypocrisy. Walt's character arc was about accepting that he did everything because he enjoyed the power. There are multiple instances where she enjoys her newfound power just as much as Walt did, but she is never forced to face this fact. Walt did much worse things than her, but by the end of the show, he was able to be honest about why he made certain decisions, while she just continues playing the victim even though she made plenty of bad decisions herself. People will always sympathize more with an honest villain than a dishonest victim.