Embedded so deeply in the operating systems of our inhabitants that unjust scapegoating is inevitable to maintain group cohesion. What's a few unjust persona non gratas if collective sanity is maintained? But I would prefer if it was a conscious decision, a just trial, but that would destroy the purpose of the mechanism wouldn't it. Every group makes an example of someone just for demonstration purposes.
The entire purpose of Christianity, historically, is to end that practice (i.e. Jesus was meant to be the last "unjustly scapegoated" person in history).