I'm sure some if you might know me (*grins* I'm inescapable) I spotted a traitor on here and had to take appropriate measures *cough* and saw this and thought I would throw my 2 cents in
I dont know where the op got the "most" figure opposing prostitution... I would say that's a little but of an exaggeration. When it comes to modern feminism but really the main form that is opposed to it in a moral sense and male oppression is radical feminism. Marxist and social feminism are opposed to it as well but for a different reason; to sum it up, not male oppression but as a result of socioeconomic and class oppression (though they advocate for social structure change/ end to capitalism, and do not believe in the criminalization of it.)
However sex positive feminism, different forms of liberal feminism and existentialist feminism do not have qualms with prostitution as a profession and find it liberating to different extents. The woman has the right to control her own sexuality, which includes the right to use her sexual capacities to make a living.
Though the position of the above is taken with a bit of caution by some. And which is my view point in this, that there is a ring of truth with socialist and Marxist feminism. Many women are forced into prostitution be it coercion, trafficking, as a last resort of economics etc. However I see the reason for this is that we delegitimize prostitution and throw it to the fringes of society, thus leaving it open for it's seedy aspects. It's not the opposition of sex work in itself but the stigmatization of it.
By legalizing we give it legitimacy and open the doors for a more positive work environment. It opens it up for regulation which can give the upper hand and more control to the women. It also begins to weed out the abuse, violence and oppression that thrived because of delegitimization. Ie, it becomes more of a choice for women.
As Kamala Kempadoo would argue; By conceptualizing prostitution as a form of labor and avoiding moralistic discourses about sexuality, feminists can avoid unrealistic abolitionist approaches. Instead, they can address the problems of prostitution in terms of working conditions and worker empowerment, the legal status of the work, and the occupational alternatives available to people oppressed by race, class, gender, and nationality.
And we can't forget about all the male prostitutes out there
On a side note there was a recent demonstration in South Korea that gathered 1600 sex workers to protest the toughened prostitution laws and recent crack downs.