The enforcement of morals by edict is always questionable. We have had regulation for long enough (brothels 1885; soliciting 1959) to find out it does not work in preventing the behaviour it is supposed to control. Instead we have at best a waste of police time in attempting to enforce these laws, and at worst a pushing of these activities into criminal hands.
The dangers of sex work are considerably increased by its being covert, and the fact that the law will not protect sex workers; violent people prey on them with impunity. The currently covert nature of sex work allows abuses including trafficking (the extent of which is, I think, exaggerated, but anyway it could be all but eliminated if sex work were treated like any other kind of work – how much trafficking is there in legal occupatons?). The worst aspects of prostitution are its dangerous and unsanitary working condisions, which are entirely a consequence of its illegality.
The acts involved in prostitution are not intrinsically bad and are, indeed, the basis of many a marriage settlement. Whether prostitution is criminalised or is legalised, as in New Zealand and Holland, is a matter of national choice. We can choose to give sex workers the protection of the law, and the maintenance of decent working conditions. We can choose to save on policing and court time, and we can choose to receive taxation income from a legal business.