Isn't humanity acting out a reflection of its desires, where the ends justify the means?
The post is using an argument from human nature, to illustrate the evil potential of man. Psychopath may not be the correct term linguistically, this doesn't take away from the perspective.
i don't understand what you are trying to say
Within every human there is a capacity for great destruction, to oneself and other individuals, which can be manifested physically in the horrors you described. No-one morally is spared from blame, it just depends to which degree what we are doing hurts others.
Anyone thinking the evil potential isn't innate biologically and under a correct circumstance wouldn't surface is delusional. This is the literal Jungian shadow.
E.g. your village has been destroyed by invaders as a child, killing your father for example, decades later leading you to lead a brutal dictatorship out of anger; enforcing that anger on untold others. Everything the now old man would enforce would never bring back his father.
NB I also have this perspective.