“My question here is why do we humans keep doing this to each other or to ourselves? Why do we think so little about the role of humanity and of kindness?”

Buffalo Rising interview (2007)
Context: Even when someone from the lower financial caste in, say America, "makes it," then there is this other barrier of old money vs. new money, social status, respected family names vs. unsavory familial relations or even ethnic background that makes the entire journey of achievement suddenly turn sour and seemingly not have been worth the while.
My question here is why do we humans keep doing this to each other or to ourselves? Why do we think so little about the role of humanity and of kindness? In my opinion, if we believe in a higher being, there is only one God and he/she is neither you nor me. The sooner we begin this process of healing as people, all people, the sooner we can begin to live a mutual life free from innuendo, hurt, judgment and need.