A banjo is a human construct, that doesn't make it hurt any less if you get hit with one. Human construct can be as real as any natural construct.

I'm not sure I understand what exactly it is you're arguing, you seem to be in favor of the rule of law that dictates and punishes egregious human behavior, but also are arguing that such behavior is simply people exercising their nature. Do you believe that people can choose to go against their nature, and choose to reject acts that might cause harm to another?