So, I've decided to write this because when I first joined this club, a year back, it had more than 1000 fans- now its come down to 597.
Mostly its because people hate Sasuke for all that he's done. I'm not saying he did the correct thing, I'm simply justifying two of his great sins (as put by a fellow Narutard).


It wasn't the correct thing to do. But Sasuke did it without knowing the real story. He did it because he was led to believe that Itachi had massacred their whole clan out of his own free will.
If you grew up attached to your family, and with an older brother who you hero worshipped and who loved you more than anyone else. And then, one day, you returned home to find out that very same brother killed your whole clan.You'd want revenge as well.
And that is exactly what Sasuke did. Revenged the death of his whole clan.

Also, after finding out the truth, Sasuke totally repented his doing. He cried and he repented over his doing in more ways than one.
Itachi wanted to be killed by Sasuke, as Tobi pointed out. To Itachi, being killed by Sasuke was his way of penance.


It wasn't the correct decision and neither would it make Itachi come back to life.
So why did Sasuke decide to do that? One word answer: Revenge.
Ever since, the Uchiha clan was massacred, Sasuke was a revenge driven person. And old habits aren't easy to let go of.

The reason why Sasuke decided to destroy Konoha is that it was because of the elders, namely, Danzo and the counsellors- that Sasuke lost the person most dear to him.
It may be stated here, that throughout the series Sasuke was 16- which is an age far too prone to influence, and the Akatsuki tricked him into deciding to destroy Konoha.