Question

Why Itachi Uchiha killed everyone of his clan?(naruto)​

Answer 1

Explanation:

Itachi killed his clan because the Uchihas were trying to take control over Konoha from the village elders. In order to stop another war Itachi killed his parents and clan.

Answer 2

Explanation:

because the uchiha clan has decided to take control of the konoha village by controlling the 9 tailed beast which is in naruto.

so the third hokage and danzo requested itachi to spy on his own clan and after confirming that the plan was true , they ordered itach to kill everyone of his on his own.

And itachi was never forced to do it , he made his decision on his own and he is very loyal to KONOHA.