i mean you cant expect a person to be sane when everything they known is a lie. Sasuke had his family killed by his only brother only to find out after he killed his brother that the elder and Hiruzen pulled the biggest bitch move in naruto history by ordering itachi to kill his own family. I mean Hiruzen didnt eve have the ball to do it himself but instead he made itachi do it.
Of course you will do anything to get revenge for your clan. One clan mudered by by one person......after that the uchiha's pride went down the drain as well. It wasnt even a fair fight. Itachi killed them while they was eating dinner,sleeping and with their sharingans down. Even when itachi got in their face they never suspected him to kill them. They turned their backs to him caus ethey trusted itachi.
