"If sex workers claim they aren’t victims, we expect them to say they chose sex work voluntarily, that they find their work fun, or a therapeutic public service, that they are empowered. We’re not satisfied if they say that it’s a crappy job, but they’re doing OK. But why should workers have to be having fun, or be satisfied with their job, before they can earn the right to join a union, or have legal protection from violence?"
I am put in mind of the Borgen episode where Birgitte Nyborg wrestles with whether prostitution should be legalised, the relationship with human trafficking and so on. But even that did not go so far as to have the sympathetic sex worker say that it's a pretty rubbish job but, even so, that's no reason why we or our clients should be in trouble with the police.
There is a straightforward libertarian position: so long as there is no coercion, there should be no criminal sanction. But in this context, we suddenly find libertarianism at its least inspiring. We are not talking about JS Mill and experiments in living; we are not talking about a thousand flowers of freedom blooming; we are not with Pitt the Elder proudly declaiming "The poorest [sex-worker] may in his cottage bid defiance to all the forces of the Crown. It may be frail — its roof may shake — the wind may blow through it — the storm may enter — the rain may enter — but the King of England cannot enter — all his force dares not cross the threshold of the ruined tenement!" We are simply saying that if consenting adults want to engage in an unsatisfying and rather regrettable line of employment then they may. It's the argument you could make for legalising working in a call-centre or as a dwarf for being thrown - but only if you couldn't think of any better argument.
Indeed, it is so uninspiring that it isn't the argument that anyone actually makes for legalisation. If you're a feminist or a conservative then you can say that you are in favour of protecting vulnerable women (who isn't?). If you're on the left you can argue for empowering people to lead valuable self-actualised lives through sex work. If you're on the right, you can say that it's always going to happen, so why bother the police with trying to stop it? They all have more persuasive force than saying rubbish jobs should be legal too.
I agree with the premise of the rhetorical question in the quotation. Everyone's job has good bits and bad bits, and you wouldn't want to have to persuade the state that your job had enough good bits to it before you were entitled not to be beaten up or raped for having that job. But I would stick with the happy hookers if you want to change the law: you already have the libertarians on your side - it's the others you need to worry about.