This is true. I guess, though, that the vast majority of prostituted people are not entrepreneurial, and even many of the "entrepreneurial" types might also have been forced (even if by extreme circumstance if not by a gun-to-the-head situation) at first. I'd like to stop thinking about this so much---at any rate, I thought the similarities of language between the two instances--and the point that language can easily objectify people by calling them a noun fashioned from a condition rather than an identity--was interesting.
There can be parallels to slavery; depends on the situation, I think. To be sure, sex trafficking is alive and well, and is a very literal form of slavery. I wouldn't hesitate to describe the victims as "prostituted whomevers," be they men, women, or children.
I can't apply the same term to the entrepreneurial woman who discovers she can make a small fortune working in a legal brothel outside Vegas. All prostitutes are not the same, and all are not victims.
Interestingly (at least to me), this is similar to an issue I encounter frequently in my job. It is the current practice in history to refer to what used to be called "slaves" as "the enslaved," or to say "enslaved woman" or "enslaved man" rather than "slave" as a stand-alone noun. The reasoning is the same as the one cited here--to recognize that slavery was a condition, not an identity. By calling someone a "slave" you make the identity the same as the condition--the human is defined by what was done to him or her. By calling someone "enslaved" you point out, subtly to be sure, that the condition was put upon the person. I guess you could argue it's semantics, but it makes a big difference. And I'm not saying slavery and prostitution are the same, though some might argue that (or not)--just pointing out that the language issue is very similar.
I do know that it makes a big difference to women I know who were coerced into the industry (whether as children or adults). Typically, once someone is described as a "prostitute," that is seen as the be-all, end-all of their identities, and it's dehumanizing. The thinking is: one wouldn't call someone who had been robbed "robbery," so in those situations where an individual has been forcibly prostituted, one shouldn't call them "prostitutes," either.
I'm not one for political correctness, to be sure. Rather, I'm for accuracy, and this is, in fact, a term in use by many women who have this shared experience. Which is not to say that all women in the industry use this language (plenty are more inclined toward the far more "politically correct" moniker of "sex worker," for example), either before or after their experience in the industry, but it is an important term among those who advocate for the needs and rights of such persons. (Often, of course, such advocates are themselves self-described survivors of the industry, or "formerly prostituted women," just as women working against domestic violence may describe themselves as "formerly battered women.")
I realize the term is controversial; those who use it (especially self-identified survivors) are often targets of ridicule, accused of "political correctness" and the like. But in a society in which NHI (for "No Human Involved") is sometimes stamped on the law enforcement case files of prostituted women who are victims of homicides, it's not, in my opinion, a trivial or merely "semantic" distinction, to employ language that specifically takes notice of their humanity, rather than simply discounting them as "prostitutes," "whores," and other (arguably) derisive terms.
Does calling a prostitute a "prostituted woman" really humanize the woman? It seems like a minor semantic variation, and while it might be more politically correct, I don't know that it makes any difference.
A handy alternative to calling trafficked women "prostitutes," which recognizes the humanity of the individuals concerned, and whose identities ought not to be conflated with what is, to many such women, an experience of ongoing serial rape, typically controlled by pimps.