Blaxploitation certainly perpetuated stereotypes, but, perhaps more importantly, it employed a lot of black people, and it was a brilliant form of self-expression that was from the heart, with no significant contamination from those jive turkeys in the Hollywood establishment. It was gritty, but then life in the inner city was often gritty. Believe it or not, almost every blaxploitation film ends with a very responsible and empowering message (i.e. the pimp leaves a life of crime in favor of the straight and narrow life).
The films also popularized the flamboyant fashions that were beginning to become popular in urban areas. The August 1972 issue of Ebony summed the trend up pretty well: