A kid named, X, was living happily with his friendly neighbours, Y & Z. But there was animosity between the parents of X, Y & Z (respectively, A, B & C). Then, one night on the return from a holy place, A's parents M & N, and some others who were of old age & felt they had earned enough virtues through their pilgrimage were coming back; but some other miscreants, H, J, K & others joined forces to attack on that returning vehicle. As all those old folks died instantly in the fire. A & his friends, D, E, F decided to attack local homes of H, J & K which turned out to be near B & C's place. On this attack, B & C found an excuse to add fuel to their old animosity by assaulting A's house. This caused A to die & eventually led X to take revenge on his father, A & grandparents, M & N's lives. X took out B, C, & his long-time friends Y & Z. He turned into such a killing spree that he killed/attacked most of the associates of B & C, including P, Q, R, S, T, U, V etc. The government eventually caught X. He confessed to his crimes. He asked the judge, when his grandparents (M & N) were brutally burned in the vehicle, he kept quiet. He did not agree nor disagree with his father, A. But when his father, A was also killed by his friend's parents, he could not bear it any longer. Ask yourself: if you were in X's place, what would you have done? Would you keep quiet to watch your grandparents & then your parents die mercilessly? What would your reaction be? How would the rest of your childhood be? What dream would you be dreaming growing up when all your close family members are gone & you have no one to look up to, no one to take care of you?
I'm not saying it was justified to kill 3000 people harshly is acceptable. But put yourself in the shoes of that kid, X. What would you have done? I know you might say if violence will lead to violence, then there is no end to it. But losing everyone in your family, could a normal human being stay peaceful, quiet, unmoved, unresponsive? Even if so, for how long? Will there not be an outburst of emotion which can come out as burning fire & raze through others in his way? Isn't that what has been shown through our Parshuram avatar's legacy?