The basic question of why is prostitution illegal is probably along the same lines of why sodomy was illegal up until quite recently: no one bothered changing or challenging the laws.
I think there's more to it than just that.
The duality the United States has with it's attitude towards sex is just scary. I've met some people with whom I've told them that I make pornography and they seem to be alright with it, but when I tell them that I believe that prostitution should be made legal to help protect the women involved in the industry, I get a lot of animosity.
.....seems a bit sexist to me.
The point I'm trying to make here is that legalizing prostitution isn't going to happen until attitudes change more. Right now, a woman who has a lot of sex is still labeled a "slut" and even though it's more understood than it was 40 years ago, it's still a negative thing. A prostitute is still stereotyped as a drug addicted, no-talent, lazy, beaten woman, when in fact, that's not the case most of the time.
Most models I've met to work with, some of them prostitutes, are very intelligent, wonderful people and I know one of them who has been a tea-totaler all her life.
There's more to being a prostitute than just lieing on a bed with your legs spread, but people don't see that.
Anyway, the laws aren't going to change anytime soon because of this duality. It took a long time for gay people to be accepted (hell, it took a look time for gay people to be considered insane), and it's going to take a long time for legalizing prostitution to happen. Just look at the arguments that the opposing view has.
By the way, human trafficking is definitely NOT unique to the sex industry. If I recall correctly there was an article in Newsweek (I have to look it up) stating that there was a lot of human trafficking to divert people to pick the plant that makes chocolate....
Stamping out prostitution is not the answer. Trying to do so has only made a bad situation worse. The women involved are the ones who suffer the most by this way of "protecting" them. I honestly don't see how keeping prostitution illegal protects the women at all. In fact, I don't see how arresting a prostitute and her john would stop human trafficking or drug pushers or violence. Everyone here who opposes the legalization of prostitution hasn't given any form of convincing argument to me. Sorry, all I hear is a bunch of fear mongering, moral stance and spin doctoring that just doesn't hold water for me. No offense, please.
Seems logical to me that legalizing it will give women in the business at least some avenue of legal protection, give them more choices and make the ones that are there easier, gives them health care, and yes, more independent. Not to mention how much money the government is missing out on taxes with this.
Just seems to me that opposing it is just "old world morality": "Hey! How would you like your daughter or your wife to be a whore?"
My answer, honestly: "If she was smart about it, safe, no fear of being arrested and very happy with what she's doing: I will support and love her still."
Sorry for the rant. It's 4:30am on Saturday morning.... felt like I had to say something....