Fathoming the Enigma

Human is an unfathomable one, is a widely accepted and oft repeated maxim. But why do we declare and celebrate our status as an unfathomable one? Why should human, unlike all the other forms of life, possess such a destructive trait? I think, we need to ask such a question, if not coming up with an answer. I know, there are many, who are always there with remedy for it. Perhaps, we are deriving benefits out of our unfathomableness. We need to identify those and prescribe remedies for it.