Why do you assume white people have no stake in the matter? White people who want to end racism do have a stake in the matter because we support the people who are tired of being lampooned in a racist manner. 
Lampooning and stereotyping groups of people who have been racialized in the US serves a function--denigrating them. The purpose of denigration is to signal that the lives of those who have been ritualistically denigrated count for less. Both minstrel shows and lynching are institutions initiated by white people and they played a fundamental role in keeping African-Americans in their "place."