Most hookers are forced into prostitution by poverty or traffickers. In the sex trade, markets fail. There are always more willing buyers than sellers, so unfair means are always used to increase the supply.
In a perfect world the sex trade would be fine. Our world is not perfect. While I admit this view will reduce the right of a few women willing to sell themselves, and the many men willing to buy sex, it protects the rights of people being exploited.
I am unaware of any place or time where legalization of the sex trade was not accomplished without much human misery.