Why "human nature" takes a higher priority than "common sense".

Human history is rife with people fueling vicious cycles, most notably surrounding conflicts between certain groups of people like we see today. These cycles are excused under the crutch of "human nature" but wouldn't exist if those people stepped back and thought "wait a minute".

When I was little, me and my siblings were taught that our outcomes are our responsibility and that our physical/neurological/psychological shortcomings are no excuse for a member of society, so when I see someone talk about someone having done something wrong and say "it's only human nature", I just want to say "dude, I'm a woman with several medical conditions and yet you're worse than I am if you use the plain fact that someone is human to justify their behavior".