I disagree. When I was a kid, back in the '60's, the schools for black students were really awful. They had no funding, inexperienced teachers and terrible facilities. Schools for white children had much better everything. And this was in "liberal" Connecticut. It was no surprise that the children who came out of these miserably deficient schools had an inferior education.
Then affirmative action came along. All of a sudden kids from those schools were going to be affecting the academic performance at many colleges and universities and government entities and many corporations were going to have to hire those kids. So, after some whining and waffling about funding and such, a bit more money started flowing to the awful schools. Colleges and universities started sending students to help out at the schools and corporations started giving grants for equipment. While the inferior schools didn't transform into Harvard over night, they did improve tremendously. And wonderfully, kids who would have had no chance in the old system simply because of the color of their skin, got a chance at a real education.
It wasn't a sudden burst of altruism that brought on the change, it was pure self interest. The colleges and universities realized that without good academic grounding the kids from those schools would bring down their graduation rates. And government agencies and corporations realized that if they were going to be hiring those kids, it probably would be better if the kids had a real education. So the kids got an education and went to college and the result was a competent more diversified workforce.
The number Affirmative Action people at any single school or place of employment is quite small. And the people "replaced" by AA wouldn't have been any better academically or as employees. People with good academic or employment records are not the ones affected by affirmative action quotas. Anyone threatened by affirmative action quotas just needs to work hard enough to get out of the "low performing" group and they won't have to worry about being replaced.
Affirmative action has made schools and work places better for everyone by making a defective and highly biased system a little less biased. It's given a chance to people who before AA, would have had no hope no matter how smart they were. Speaking as someone who saw what things were like before AA, I'm pleased with the results.