When you do the math it's really the vestigial remnants shared with inhuman primates, which have not been completely overcome by the process of civilization so far, that underlie the need for so many laws that would be completely un-necessary if everyone was fully steeped in extreme true
humanity and behaved that way all the time.
Too bad we are not evolved enough to have left all of this inhumanity behind along with the extinct hominids, but you have to play the hand you are dealt.
When you think about it though, what most people usually call "human nature" is actually really inhuman nature which has not been fully surpassed.
They wouldn't say it if it wasn't false ;)
Also widely regarded as an excuse to begin with even if not fully recognized as such.
It's always been plain to see the world would be a better place the more inhumanity has been eradicated, but there have always been those who favor more inhumanity not less anyway.
Maybe some people have always been concentrating on their limitations rather than their possibilities, and that's been the limit of their horizon historically since the dawn of man. Others, not so much.
Full "human nature" would be the complete absence of inhumanity in thought & deed.