Another angle to prostitution is that the fact is that there are large numbers of men in the world who simply cannot get physical contact from a woman. Yes, often the men can do a lot to improve their lot and attract the opposite sex, but the fact is that there are also many men who have irreparable physical issues going on that make them sexually undesirable to women. Making prostitution illegally essentially declares to those men, "Sorry, no physical contact for you! EVER!"
Doesn't seem right to me.