Why do some people hate Sasuke? They don't understand him, simply put. In fact, they don't try to understand him. When people think of Sasuke, many different things come to mind. Maybe traitor or avenger, psycho or b~stard. Hate, revenge, strength, bad~ss. People allow themselves to see a single face of Uchiha Sasuke. They let themselves see the Sasuke who hates Konoha, who wants revenge for his brother. The one who wants to take out everyone in the Hidden Leaf, including people who had nothing to do with it, without reason. The one that is supposedly off his rocker and insane, filled with hate and power from the hard life he's lived. Those who hate Sasuke, I believe, only allow themselves to see what's on the surface. But, as Kishi has tried to teach us, we all must, as fans, try to, "Look underneath the underneath." Because the truth is? When I think of Uchiha Sasuke, I think of light.
Kishimoto's characters all have their fixed roles. Naruto is the traditional protagonist. Sasuke himself is the friend-turned-enemy. Tobi is the main villain. Everyone's roles are set, not in stone, but fixed, for the time being. Naruto is the hero who can change anyone's heart. Tobi is the man who has f~cked up many people's lives and strives for a forced, corrupt "peace." But you cannot let their role be the only influence on your opinion of them. Uchiha Sasuke is strong, hateful, and a bit crazy at times, but that is not who he is. Yet this is all people who hate him see. Someone who defied the wishes of the very person who lived for him. Someone who doesn't seem to care about others. Yes, he didn't do what Itachi wanted him to, but this is a boy who has lived half his life chasing after revenge, living as an avenger. His hatred had grown and manifested and he was fully prepared to bury it with Itachi after killing his brother, finally. But then, alas, Tobi pulled him away, told him the truth, and that hatred, that hatred that had certainly not died away with Itachi, lived on and grew even more after Sasuke was let in on Itachi's lies. Sasuke only seeks revenge at this point, because he's filled with some of the rage and hate that he felt against Itachi for so many years and now new hatred and anger directed at Konoha, too. But you have to remember where Sasuke started.
Why does Sasuke want to destroy the Hidden Leaf? Hate. Why does hate exist? Because of pain. And what enables pain to exist? What causes it? Love. Uchiha. Sasuke. Feels pain. Dread. Heartache. Rage. Hatred. Lost. Betrayed. Forsaken. And, somewhere, alone. Because he is in pain, he is trying to find a way to ease that pain, via revenge. He sees darkness. But, also, I know he sees a light somewhere. And that's the light we all need to concentrate on every single time Uchiha Sasuke is on screen or in a panel. Somewhere in there, there is a spark of light. Somewhere. And, one day, it'll be ignited and Sasuke will change. We just have to wait. But he's not all bad, I promise. Think to how he's responding to seeing Itachi right now, or how he interacted with Naruto the last time they met. Think of how he's planned to keep his promise with Naruto.
Also, with this, I'd like to make a reference to the Homunculi from FMA, perferrably the first series from 2003. Look at Envy in my sig. Do you think he was completely evil? I think he was pained. Do you think Wrath was just an angry, psychotic yet playful little boy? I think he was upset at never getting a taste of humanity like the others got to. Lust? She wanted to be human, all-in-all. My point with the Homunculi statement is that... they were villains... but even they had good left inside them, like Lust working with Ed and then Wrath setting himself and Gluttony up to be sacrifices in the movie so Alphonse could be reunited with Edward. Just think on it. If beings with their own bodies and minds, but no souls, can have good inside them, so can Sasuke.
And to those who hate Sasuke because of what he has done, or what he may, think of this. Naruto, Chapter 577. He asked Itachi why he didn't kill him. He asked what made him any different than their parents. And he asked with desperation, clearly shown by the punctuation used in all the translations. Nearly all of his speech, at that. If you think Sasuke is a b~stard and still don't want to pay any mind to the pain he's felt, think of why he must've asked that. For comfort, from some dark crevice. And, also, think that there is a possibility that, by having him say something like that, Kishi gives off the feel that maybe, several times before, Sasuke has wanted death. Not saying that's actually it, but just think about it.
Sasuke will come around. That light is still in there. Spark, spark.
I think it's obvious I'm not a Sasuke hater. Second favorite character, right after Uzumaki Naruto.
