Well first of all, i need to clear up something for you ,revenge is never a right choice no matter how you look at it , revenge won't solve anything and will only creat more hatred and that's the reason why the shinobi world never changed , everytime people were put in a similar situation as sasuke they don't even try to understand ,they'll directly try to seek revenge just cuz they think it'll make them feel better which is absolutely wrong , just like gandhi said " an eye for an eye will only end up making the whole world blind" .
Alright now I'm gonna give my opinion about sasuke's reasons for revenge , I personally think that sasuke's reasons are not what you all guys think .
I think that sasuke is lying to himself , he's trying to convince himself that his reasons for revenge because konoha made his brother suffer and blablabla , but I think that the true reasons behind his revenge are because of guilt and anger and other stuff ,1- yea he's still feeling guilty about his brother's death and he can never forgive himself , he's still thinking that he's the reason that his brother died and it's driving him mad ,2-he is feeling lost , just try to put yourself in his position , he survived and trained hard to become stronger , he lived almost 9years of his life. Believing that he has only one reason , only one goal to live for and is to kill his big bro , then he finds out that that goal didn't even exist which means the reason of his existence.
So in sasuke's mind he has no reason left to live for, so what sasuke is actually doing is that his putting all his hate and anger towards konoha so that he'll feel better in other words , he's doing all of this to convince himself that konoha is the reason of itachi's death so he won't feel guilty himself.
