Why not legalize prostitution?

From an economic and safety viewpoint, legalization of Prostitution (Or Sex for Money) makes sense: Currently any illegal prostitution is tax-free money, meaning the government will never directly get its cut of that $20 you gave to 'Sally' for a quickie.

So let's say we open official and well-indicated places for consensual adults to get Sex for Payment. (Consort Business as it would be called, has a nice right to it):

First Effect: For one thing, Pimps and Street-walkers would soon be driven from said streets. There would not only be competition, but competition which would not be barred down by Police.

Second effect: These 'Ranches' or whatever they decide to call them, would pay taxes as any other business would, so the government can get a slice of that. The business-owners and sex workers themselves would also get a cut (And to keep costs down for the customer, I imagine the workers would be salaried and get most of the money from Tips, as do Waitresses, Pizza Delivery people, and so on).

Third Effect: Sex Workers would be protected from violence and have access to (probably) great Health Plans, as well as required screenings for STDs and the like. Meaning the chance of sleeping with an infected person goes way down.

Fourth Effect: Infidelity and Rape crimes would probably go down. If some idiot really wants to get screwed, he can pay out the $100 an hour and be done with it, instead of going out and harming some innocent woman (or man!).

Sorry Divest, but I support this. The only real opposition is from a moral standpoint, and even then, one could argue that opponents would rather have Consorts be harmed rather then staying safe. The thing is, when people think of 'Legalization of Prostitution', the mental image is that now the street-walkers will continue forth, but with no penalty. If supporters want even moderates to support the idea, they need to drill into the voters mind that Legalization = Ranch-Style Bordellos, and that Street-Walkers would now be extra-prosecuted, as there is now a legal and safer alternative. However since its a good idea with lots of Pros and Few cons, the current congress and/or administration will vehemently oppose it, since they seem to oppose ANY good idea lately.

Jam it back in, in the dark.

I just remembered the question that puts things in perspective
for a lot of people:

Why is it illegal to sell something you can give away for free?

There's nowhere I can't reach.