Define affirmative action. Why is it so controversial?

Affirmative action (employment equality): is a practise or policy that used to eliminate or improve the educational and job opportunities of minority who suffer or historically have suffered from discrimination because of their religion, race, colour, gender etc. and ensure that an individuals are employed, and that employees are treated failrly and equally during their employment.

Affirmative action has been controversial as it's result in reverse discrimination. It's might considered as an insult to an individual(s) who want(s) to show that they are not less qualified candidates merely because of race or gender and they are equal to other individuals and no longer need special consideration and lower standards in order to get a job.

Affirmative action is a term used to identify policies or programs aimed at levelling the playing field for minorities in the pursuit of jobs, admission to colleges or universities or even government contracts. Affirmative action policies have been established in response to decades of discrimination against minorities, even after the passage of constitutional amendments and federal statutes prohibiting discrimination on the basis of race or ethnic origin.Affirmative action remains controversial not because there is widespread public sentiment in support of racial discrimination.
At Least in the scientific community, I doubt the authors won much respect by publishing this as a popular science book rather than a piece of peer reviewed research. Many scientists later criticised the methodology of the research, and I imagine cannot have been happy that such a controversial piece of research in their field decided to entirely side-step the peer review process that might have caught some of these problems earlier.

Thanks!