I don't see any reason why someone who wants to sell sex shouldn't have full and unfettered freedom to do so. It's not really my cup of tea, but to each his own.
When you get right down to it, this particular sort of prudishness historically stems from a desire to keep women economically dependent -- after all, people rarely bitch about the men who purchase sex -- and as such, we should think carefully before perpetuating it. I know that full acceptance of sex workers is probably too extreme to expect, but perhaps we could collectively come to some middle ground opinion such as, like cleaning toilets and working at taco hell, it's kind of a gross job, but somebody's got to do it.