Why stereotypes?

I'm a brilliant, properly raised half black girl, # 7 of my grad cl. My dad ( black man) is a highly ranked retired member of the US Air Force and now an Inspector of Raytheon Co. doing airplane engineering. My question is why the hell everyone has stereotypes that black men produce babies and leave their baby mamas. My father is still with my mother. So what makes someone think that all black people are pathetic or on welfare, cause lots of people (especially white people), just throw stereotypes right and left at blacks. There are white, mexican and asians who desert their children, go through abuse and all that negative stuff that is umed to go on in only black communities. more than 70% of school shootings are done by white people. more than 80% of suicides are done by white people. so why is everything thrown on blacks?! not to mention that black guys get the short end of the stick in the judicial system. why are people turning a blind eye at the 'other' races' flaws?