it's not self-destruction if the woman chooses to do it. sure, it's possible that's an underlying cause ...
people get into prostitution primarily because they have hit rock bottom, and as they have no skills or degrees, or perhaps they have a criminal record barring them from most employment, they need to make money. and they WILL make money. a lot of it. a lot more than working at mcdonald's. a lot more than most office jobs, too, if they're hot and serve "upper class" clients.
and remember, men are prostitutes too! perhaps even up to 20% in america are male (based of arrest statistics).
another prevalent reason for someone to be a prostitute: force.
illegal harboring, kidnapping, and coercion happens every day. it's already illegal to be a john, so what's the harm in renting someone who's there against her will?
people are imported here from other countries occasionally but more often than not it is a case of someone kidnapping a 14 or 15 year old girl and getting them into the business by trumping up their online profiles to say they're only "escorts" and are "of age". this is a huge problem, bigger than most people think.
a brothel would not employ this tactic. the overall demand for illegal sex would go down, as there is a legal alternative.
the need for abusive pimp syndicates would go down as they would have to drop their prices to compete with the brothels.
the law in nevada is imperfect. it allows prositution outside of brothels as well, which still supports pimp<>whore behavior (which is never good--it's almost like slave ownership).
also, sometimes brothels will "slip between the cracks" and go un-regulated. This can result in problems, abuse, and rape. So, should we ever legalize it, it should be only under strict supervision.
If human trafficking, ties to drug abuse, STDs, and harassment/abuse were uninvolved with prostitution--i.e. if a woman could just turn tricks sometimes on her own with no recourse, then it'd all be peachy and i'd say legalize the lot of it. but there ARE problems with it stemming beyond simple religious morality.