Because that's the only trump card that black people have to play, the race card. No matter what, they can blame it on racism more than not people will back off in fear or being labeled a racist.
Affirmative Action is bull####. Being a 'minority' myself, I'm fed up with the inequality amongst minorities.
Affirmative Action is meant for not basically just blacks and hispanics. The two largest minority populations, but also the two minority populations with the largest population of uneducated and poor.