It's the nature of humans, also the reality of nature. Only the strong survives. From the day 1 we learn how to survive in this life. We build an armor to defend our mind, body and soul. If we were weak we couldn't survive in this life.
Why do you think the strong survive? The strong all die, just like the weak. It is the humble who are strong.
People walk all over grass. Yet there are far more blades of grass in the world than there are people.
EDIT: And think of the cockroaches. The non-human ones, I mean.