Pin it on the pimps, say the signers of an open letter to Amnesty International. "[H]uman beings bought and sold in the sex trade, who are mostly women, must not be criminalized." However, what your 'Draft Policy on Sex Work' is incomprehensibly proposing is the wholesale decriminalization of the sex industry, which in effect legalizes pimping, brothel owning and sex buying.
Prostitution probably isn't "the world's oldest profession," as some like to call it -- hunting and gathering likely briefly preceded it -- but it's certainly close. Anything that people value, they'll buy and sell.
Most people value sex, exchanging it through various barter systems. Dinner and a movie for a one-night stand. Perhaps a set of rings and commingling of property as part of a lifetime arrangement understood to include, among other benefits, physical intimacy.
Or, back to that movie, the price of a ticket for a vicarious but nonetheless titillating experience featuring the likes of Debra Winger, Lena Dunham, Meryl Streep, Anne Hathaway and Kate Winslet, all signers of the letter.
Amnesty's critics have it backward. There's no sex work without sex workers. Pimps can't broker transactions in, nor can "Johns" purchase, something that isn't for sale. And as the public-facing part of the business, the workers are the easy ones to detect and to persecute. Where prostitution remains illegal, it is they who suffer.
On the other hand, if prostitution is legal, the specter of "human trafficking" will inevitably decline.
As we've learned from alcohol and drug prohibition, criminalizing trade in something people want merely pushes that trade into the domain of players who are willing to risk arrest -- and resort to violence -- for profit.
Legal prostitution might or might not be pretty, depending on one's personal moral views. But pretty or not, criminalizing it only makes things worse. It actively harms the women who are the vast majority of sex workers. It corrupts law enforcement. It exposes sex workers (and their customers) to unnecessary dangers. And it empowers violent pimps and human traffickers by making their way of doing things profitable.
I prefer to give the celebrities who signed this letter, and who have taken up "stopping human trafficking" as a personal crusade, the benefit of doubt. I don't think they actually hate women in general, or even female sex workers. But if they don't, they should support Amnesty's call for decriminalization.