He did make mistakes, though.
Summary:
- Sasuke is a pretty controversial character in Naruto, but he definitely is not evil.
- While he did try to destroy Konoha, it was because the village's government was behind his family's death.
- He got better eventually, and redeemed himself by saving the world with Naruto.
Among the characters of Naruto, perhaps the most divisive one is Sasuke Uchiha. The deuteragonist and the rival to Naruto himself, Sasuke has done a lot of things — both good and bad — and his actions heavily influenced the plot.
At some points, Sasuke was de facto on the side of the antagonists, which, to many, means he was evil. That notion, however, is completely wrong: Sasuke made a lot of mistakes, but he never was actually evil.
Sasuke's Attitude Is Easily Explainable
First of all, Sasuke's attitude towards Naruto in the first half should be explained. At first, Sasuke had no respect for Naruto, openly mocking and taunting him for lacking formal training and ninja-like qualities.
Still, this doesn't mean he hated Naruto — in fact, this kind of behavior quickly turned into mutual respect and a semi-friendly rivalry.
Sasuke's brooding behavior from his academy days is also entirely understandable. He's not just arrogant or stuck-up (okay, maybe a little bit). He's a traumatized kid whose entire family was slaughtered — give him a break.
Why He Wasn't Evil
Later in the series, Sasuke leaves the village to join Orochimaru's experimental facility, believing he can get stronger there. His end goal is to kill his brother, which he does eventually achieve — but the revelations Tobi gives him set him on a new path.
Sasuke vows to destroy Konoha, and his motive is perfectly understandable.
The village, the entire system behind it, was the reason his clan got killed. It's hard to blame him for that, and fighting an oppressive government (which Konoha, especially under Danzo, can definitely be classified as) is not evil per se.
Even later, he regrets this, and says he wants to become Hokage — not to destroy the village, but to change the established order. While he doesn't become one, this attitude of his shows that he wasn't evil after all — he just wished to correct the injustice.
He Redeemed Himself
Sasuke definitely did many terrible things — like attacking his former teammates, siding with the enemy of the entire world (even briefly), and attempting to kill those who stood against him. You can say, though, that he definitely atoned for his sins by saving the entire world and admitting his failures.
Moreover, his actions led him to the life he lives at the end of the series. That is, traveling the world in search of his own purpose — he spent so much time in his youth chasing false dreams that he can't really find a place for himself.