He can be a jerk, but I actually find him fascinating as a character. I'm not really into main characters like Naruto, who are perfect in the way that they don't make emotional/human mistakes (just clutzy ones XD). I like a character that makes errors in judgment, betrays, but atones/protects in the end. I like to watch a character grow --- not be an angel since birth. Because I feel like I can relate then.
Not to mention he's got one seriously effed up brother that screws with his head --- that had to do some mental damage to the kid. >_>
Anyway, that's just my opinion.