I know many women who admittedly and quite openly have been in the sex industry, as strippers, pole dancers, porn stars and prostitutes. They have all been at a desperate point in their lives while they did these jobs.
I worked the sex industry myself. I was a stripper for a couple of years. Does my being male make it different?
The differences that legality of prostitution would make can be observed by travelling.I watched women in countries with legalized prostitution carry on their trades in a fearless and safe manner. As I travelled south, I was treated to the sort of sights I witness back home. Women slinking around the dark streets of factory districts. They are more vulnerable. Their clients are more vulnerable. It is not an ideal position in a person's life, but it has always been. Legality, as if there should be a question, only makes the situation worse. Any underground trade is dangerous, and this one is particularly so.
In the end, the act is one between two consenting adults. To intervene is a violation of personal autonomy.