Maybe. If criminalisation drives prostitution back into the shadows, and leaves workers more exposed to harm than they were, then there might indeed be an argument to find a different battleground for the moral fight, and concentrate instead on minimising the harm suffered by the women who, for whatever reason, are offering sex for money.
The great difficulty, however, is that it leaves the sex industry intact. And in all paid-for sex there is, arguably, an inherently exploitative dimension. Even if there is nominally consent, in most cases, if not all, this will be a choice that women make out of desperation, rather than anything positive. The social and economic circumstances in which a woman sees sex work as the best available option represents, in itself, an environment of coercion. Criminalising not the women involved but their clients – particularly when, as in the French proposal, it is accompanied by a properly funded programme to help sex workers into more secure jobs – may be the least-bad answer, in both moral and practical terms.
We must not criminalise abortion because that would make it more dangerous by driving it into the shadows. We must criminalise prostitution because that won’t make it more dangerous by driving it into the shadows.