she proved, in her life and her stories, that there’s nothing wrong with it.
To be absolutely honest, there isn't anything wrong with it. The worst that can be said about it is that, to some, the concept of mercenary sex is simply unappealing. Naturally, this varies from individual to individual, predilection to predilection.
To those who equate sex with intimacy, affection, or love, the idea of sex for sale may be intrinsically offensive - just as the idea of selling children (likewise equated with similar concepts) might be equally offensive to many people. The fact that people are sensitive to it doesn't make it wrong, but it certainly makes it uncomfortable for people to deal with and requires that we handle the topic with great care and deliberation.
Of course, whether you personally find the concept appealing or not is essentially irrelevant except on an individual scale. The real meat of the problem is the way in which the business in conducted and the conditions the workers and clients are exposed to.
They say prostitution is the oldest human profession, and we should realize by now that it is always going to take place in one form or another. We're stuck with it. It is a fact of human civilization. The real question is how do we choose to handle it.
If it is treated as taboo or immoral, all that happens is people feel guilty and socially oppressed for taking part - it still occurs, but people are generally more miserable about it. If it is made illegal, all that happens is the trade is driven underground, establishing a black market without regulation in which ruthless human exploitation thrives.
Now, I'm a fan of open acceptance and regulation (even if I personally find the trade distasteful). If people are going to seek out prostitutes anyway, then we have an obligation to make the process as safe and fair as possible for everyone involved. Open, transparent governance and regulation of the trade can provide that.
We license who can drive, we license who can sell alcohol and other drugs, we license who can sit you down on a couch and talk to you about your mother and all your other psychological hangups, why not license who can sell physical human intimacy? Instead of desperate, illegal workers being exploited by pimps, we could have happy, healthy, fairly-treated workers running their own businesses and collectives.
"But it will promote mercenary sex!" Yeah, maybe a bit, depending how things play out. But I'd rather have twice as many people running around having safe, happy, and fair mercenary sex than our current amount running around having dangerous, miserable, degrading mercenary sex.
Personally? The concept of selling intimacy offends my sensibilities. But then again, there are plenty of movies and books and religious beliefs and countless other things that offend my sensibilities. I can respect that other people have other sensibilities than I do, and I can respect the people who hold them despite our disagreements of taste and belief.
As long as it doesn't lead to anyone being harmed or exploited, what do I care what other people do or think or feel? It's simply not my business.