Oh, so like, NOTHING is a mental illness? Those voices in your head aren't anything tortuous which you need to get rid of? Coming to the conclusion that killing random children (with all its effects on current lives and countless future generations with what were potential scattered geniuses with cures and inventions for humanity) isn't mentally ill? People incapable of relating to any concepts which place anything else but their own personal benefit in the top position of priority? That is sane? Deciding you and your small cadre residing in drafty castles have the right to dominate the entire planet and all its life forms after an immeasurable accumulation of wealth, to initiate a program to kill off most of humanity and dominate those who remain? Because it seems to say "screw my species and its natural intention of success, as it's all about ME, my selfie, and my personal extraction of pleasure no matter the expense to others. Damn my species."
Not mentally ill, eh?
Perhaps he is correct in a technical sense. Maybe this really is the "normal" human condition when freed by infinite resources and simply left to its own individual primal instincts and devices. If that is true, then it must come down to defining what really is normal or sane, and does it pertain to survival of the species, or only extracting whatever benefit or revenge or win is possible for the self only?
At that point, it would seem our distinct concept of reason itself must be explained, since we are the only species who possess it, and yet there are so many other species who nevertheless work together for collective survival even without any ability at all of reasoning.
If they naturally try to lift their own, then why is it some of us work to destroy our own?
My personal answer would be that all such people are mentally ill, and need to be rejected.