Being cruel has a selective advantage so that trait is still in the programming. But humans have learned to override the programming. I think eventually evolution might filter out the cruelty. That is, if humans overriding evolutionary programming doesn't kill us first. The concept of gender these days is definitely overriding programming, and maybe in a very selectively destructive way. A positive feedback loop towards extinction.What would be your equivalent? Destroying whole populations, like that of a city? Selectively killing people that are not wanted?
Humans have always been and probably always will be a cruel species.