Prostitution is often equated with degradation and dehumanisation, particularly for women. Sex workers are seen as entering a market in which they are sexual subordinates, therefore perpetuating inequalities.
Prostitution actively causes gender inequality and degradation. The existence of prostitutes reinforces cultural attitudes of women being sexually subservient to men and therefore has negative implications for all women. Additionally, prostitution promotes the idea that male sexuality must satisfied, without consideration for the wellbeing of those who satisfy it.  The sale of sex by sex workers fundamentally rests on a dynamic of inequality. No woman wants to become a sex worker; it is done purely for the money which is used as an incentive to buy into a system of inequality and degradation. Functionally, prostitution is simply the mass profit of sexual exploitation by ‘pimps’. 
Criminalising women who sell sex makes women unequal under the law, further perpetuating inequality. The power dynamic found in prostitution is not unusual. Many jobs and industries are male-dominated often due to constriction of choices and ideas about ‘women’s work’, reinforcing outdated cultural attitudes towards women.  It cannot be assumed that no woman would choose to be a sex worker. The selling of sex is not in and of itself degrading or shameful. To suggest that it is is to subscribe to a hegemonic masculine world view. Therefore, the selling of sex should not be problematised; the misogynist system should be. Additionally, it is far from unusual for people to take jobs only for money, or to have jobs that rest on systems of inequality. For instance, working in a fast-food restaurant is generally a job taken for money rather than due to a passion for fast food, and is part of a business model that normally rests on the inequality of workers being paid a fraction of what higher-ups are paid while doing far more strenuous work.
[P1] Prostitution is a manifestation of the degradation of women. [P2] Therefore, prostitution should be illegal in order to reduce abuse.
[Rejecting P1] Prostitution is not inherently degrading. [Rejecting P2] The illegality of prostitution does not serve to decrease its inequality.