I think the whole thing is very difficult to deal with while it is all criminalized and taboo, in the dark and so shameful. "It" can mean sex in general, not just prostitution.

I heard recently that prostitution in "the west" has gone off a cliff over the last few generations. Recreational sex, including homosexuality and other stigmatized tastes became a more normal part of our culture and demand for prostitution declined. We stopped demonizing extramarital sex (or women, really) and the "problem" got a lot smaller. Thousands of years and thousands of cultures and god-knows how many gods worth of banning, ostracizing, preaching and tut-tutting about prostitution or promiscuity and the one thing that actually made a dent makes a difference is getting sluttier as a culture.

I think this is a metaphor for (or a specific instance of) a bigger principle.

an example

I was at university when grameen bank won a nobel prize for micro-lending. This was around the same time many governments and regulators (in a bunch of places) were trying to pressure out "predatory lending practices." Normal banks got out of the high risk, small loan business. They had a reputation to maintain and $400 loans to the broke and unemployed is not particularly lucrative anyway.

The market was left to "payday loan" shops who tended to be a lot shadier. Then the financial crisis happened and business boomed. If payday loan shops get banned (as some want), the market will almost certainly be reborn as loan sharking, a traditionally criminal trade. The deeper the taboos & bans, the worse it will get. The actual thing won't go away though. Taboos, laws or fiery political rhetoric can't make it go away. The harder these things squeeze, the worse it will get. Terry Pratchett would have been the person to describe but alas…

This is all quite ironic considering that a nobel prize was won by a bank basically doing payday loans, but with a totally different attitude. Ironic, but informative. Grameen bank has high interest rate and uses social pressure tactics to improve repayment rates, practices considered unethical in the larger financial world. Practices shared with others in this "sector" of small high risk loans to the people no "real" lender would bother with. The practices seem to be part and parcel of the market.

But, Grameen bank is not like loan sharks or payday loan shops at all, culturally. Their impact on their customers and their relationship with them (and society) is far more positive. So is their impact. They won the nobel peace prize.! The people working at grameen bank think and act completely different than the culture of the payday loan industry. Perception matters. It shapes the thing. The perception of the employees, society, etc. are all interlinked.

Criminalize an industry and it becomes more criminal (with violence, abuse and all the other things that go with criminality). Label someone a pariah and they will act like one.

Banning, or even stigmatizing payday loans doesn't make the industry go away, it just makes it uglier. Give it a nobel peace prize, and they become humanitarians. I'm simplifying, I know. But, I think this is a decent low resolution description of the concept.

It works the same way with drugs. Same with prostitution. The public perception of prostitutes, johns, madams and pimps. The taboos and laws, the disdain and ostracization. I think these things are a big part of why it is all so dark. Society tells us that it's dark. That might keep some people away, but if it doesn't… The johns walk into it knowing they are doing something bad and act like it. The pimps act like pimps with the characteristic dehumanization of prostitutes and the prostitutes, knowing that they are the lowest of the low.. they act like it. Suicide, depression, drug abuse and general self abuse and self hate.