It is only wrong because the metaphor is wrong. The root of violence lies in the nature of human beings, and how we create societies. It is the imitative drive that shapes and creates individuals and society. The clearest evidence of the imitative drive will be seen if you have a child playing alone in a room full of toys. Everyone knows the second child will want to play with the toy the first child is playing with.
Humans imitate one another.
We are copycats. And not merely dedicated followers of fashion, but we imitate one another's desires. That is why the desire for violence, once released in a society, spreads like an epidemic. The second unique creative talent of the human species is the talent to create myths. One of the roles of myth in society is to explain away the unacceptable.