Meh, I agree his backstory was kind of an asspull. I murdered my entire clan in a single night by myself, why? To test myself. Sasuke you aren't even worth killing, you're so pathetic I never loved you. I never wanted anything to do with you, I hate you you little shit. I only came back to look for Naruto and the 9 tails. Oh Sasuke Hai!! You want to fight? Ok I'd love to kick your ass.
Later On in the series
I murdered my entire clan because I was told to in order to prevent a war between them and Konoha. I had some help but believe me I didn't want to do this, it was hard enough having to kill my parents but I couldn't bring myself to kill Sasuke. You're a good kid little brother, get stronger and kill me and become a hero to Konoha. I'm only back to see is Sasuke is already and tell Danzo not to touch a single hair on his head. Sasuke? I don't want to fight but believe me this is going to hurt me more than it'll hurt you. I'll always love you little brother no matter what.
Itachi was a meh character to me. I know a lot of people love him, some even loving him a little TOO much but I may have to look at the series again and I might like him more.