I know but just curious, lets say there is no zoning laws.
As a matter of fact, I am living in an Asian country right now where prostitution is basically legal. Similar to Mexico, it is technically illegal, but it is everywhere and nobody ever gets arrested for it.
There are brothels right next to schools etc. Brothels all over, there is one in the building I live in actually. And it really does not have any negative impact on society here. The HIV rates are lower here than the USA, as well as the divorce rates and crime rates.
In the USA people have a kneejerk reaction that prostitution = horrible and scummy. But in much of the world this stigma does not exist. And making it illegal tends to cause the problems associated with it, not the business itself.
The USA is just soooooooo PC and Christian. They need to lighten up in some ways.