Probably because we are still animals and are driven primarily by the same impulses as other animals. It takes intent, awareness and conscious effort to rise ab

Probably because we are still animals and are driven primarily by the same impulses as other animals. It takes intent, awareness and conscious effort to rise above these impulses, and it provides little to no benefit to the individual. Or in other words, it's an instance of the tragedy of the commons, where the "commons" is the future of our species and the planet.