I hate him mostly because of his development. He completely ignores Itachi's wishes despite saying that he loves him and wants to destroy the thing he held most dear. F'ed up much? Not to mention how he suddenly just kills all emotions and turns into a stone cold killer/a-hole. Look at the Killer Bee vs Taka fight. Sasuke shows emotion in that fight when faced with certain doom. He reflects on what Jugo, Suigetsu, and Karin all did for him, and remembers Kakashi, Sakura, and Naruto when he awakens his Amaterasu power. He uses that to protect them, and saves Karin rather than ditch her. Very next mission. Five Kage Summit. What's he do? Goes total darkness emo mode, recklessly attacks that could very well kill Jugo and Suigetsu, and almost kills Karin just to get Danzo. He's just lost all characterization at that point and is a one-note character.