Jog.....
I got the thrust of your question when you posed it.
You are trying to understand why the left says they are pro women w/ their stance/argument, that its their body, re: abortion, yet they allow the laws against prostitution govern these same women on this sex matter.
It's simple dude, they see it as a loser that would cost them votes.
Nothing more to it than that.
You see/saw how they abandon women who bring charges of sexual misconduct against Willie, yet drag Clearance Thomas through the grinder over sexual talk.
Not one mention of rape against him, yet....
Its all about what they think will empower them ( the politician ) issues really are only a tool. Nothing more.
You saw how Senator Obama was against raising the debt ceiling, etc, then in office said it was ok, and lashed out at those who now found themselves against it.
Ditto Hillary, it was cool and patriotic to speak against Dubya, but against Her and Bo, you become a divisive obstructionist that ruins this country....
This is why you will never get a straight answer to a question buddy.
I think you know this already
I will answer you question however, strictly on merit, aside from my "beliefs".
We already have legalized and regulated prostitution.
It is called sex surrogate, and it is mostly used under the medical/psychological banner.
I see no reason why it could not expand in the hopes it might help some, with sexual addictions, get their fix without having to support an otherwise seamy business fraught with all sorts of baggage.
As with anything of this sort of nature, it would produce new problems presently unrealized. It would be up to the regulating agencies to address these matters as they arise.
It is sorta like legalizing bars. We are saying its OK to drink, yet, most folk have to drive there. Now when they leave, well, you get my point, we have now just set up a scenario for unintended consequences, on totally innocent folks.
One thing that comes to mind with making sex legal, is the emotional attachment to "love" that many bridge under the same root of their persona.
Sorta of like how VETS get PTSD from combat, or some in the medical field, who deal with death daily, become desensitized to it in order to survive the emotional conflict of their job, which often exhibits itself elsewhere in a release, like alcohol or drug addictions/abuse ( I know some MD's personally that have battled this effect ).
So buddy, I hope I have answered your question.
It is a societal equation, not moral, that folk need to weigh.
Does it produce more societal benefits, than it does negatives?
That is the question, eh?