If their goal is to protect victims then full legalization goes even further than this half-measure.
This statement has the same fallacy that the following statement does: "Keeping child labor illegal means children will choose to work in places where they feel less safe from the law. This will make young children who feel they have no choice but to work in a factory operate in a less safe environment."
The very fact that a certain choice is legal increases the economic incentives to pressure people into making that choice; in contrast, removing a choice by making it illegal incentivizes employers to offer alternate choices that are potentially less exploitative. When child labor is illegal, employers are incentivized to pay their workers a high enough wage to support the whole family without children having to work. When the option of child labor is taken off the table, workers end up in a better negotiating position.
The same is true of prostitution. When people can make money legally off of prostitution, they will be incentivized to go into the prostitution business and hire prostitutes. When they can't do that, they will be incentivized to go into a different line of work, and create employment opportunities for women that are less inherently exploitative.
>Inherently exploitative
Ah here we go. The real crux... moralism. It's exploitation at any price even if a fully capable adult makes the choice.
The parent comment is saying that if prostitution is legal but hiring prostitutes is not, then people will only hire prostitutes in areas where law enforcement is weak.
A comparable analogy would be that if laboring as a child is not criminally illegal (which it is not) but hiring children as laborers is illegal (which it is), then the people that hire child laborers will be doing so in areas where law enforcement is weak.
This seems to be both a pretty apt analogy, and also seems to be clearly true in the child labor case.
It's harder to combat rape when you have to meet client in a more secret place, and when you can't take a photo of client's id. So no, in fact actual sex workers hate nordic model since it pushes them towards more precarious position while declaring the opposite.
But the nordic model is better that the criminalization of sex workers imho.