Even for those who are, that doesn't mean that they are incapable of making decisions for themselves. Prostitutes need to be saved from themselves. If you want to patronize prostitutes, visit one with your wallet in hand. Many prostitutes are drug addicts. So are many accountants.
All prostitutes suffer from low self-esteem.
Being rewarded for being physically attractive or sexually competent is not an obvious barrier to self-esteem. Prostitution is always a degrading act. There is nothing degrading about earning an honest living the best way you know how. Some would regard janitorial work as degrading, but that's not the case either. They may have arrest records which ensure that no firm will hire them, they may lack marketable skills, they may be single parents unable to find affordable day care during working hours, or they may be homeless.