I guess everyone sees what they want to see. While prostitution certainly exists, as it does everywhere, there is much more to Sosua than that.
Aside from the periodic episodes with rain, generally the weather is beautiful, the days are consistently long and invigorating, the sea breeze is refreshing, and the water is warm.
There are a variety of pastimes, including beach going, baseball appreciating, swimming, diving, snorkeling, sailing, fishing, people watching, restaurant going, beer drinking, and to simply enjoy living.
If all one sees in Sosua is the working girls than one's eyes aren't fully open. Sosua is a very interesting place inhabited by some very interesting people. There are things to look out for, as there are everywhere, and there are things you simply don't want to miss.
All in all, Sosua is a great place to live. That doesn't mean it is a perfect place, nor does it mean it is the right place for everyone. Moreover, some people would not be happy anywhere, and for them Sosua is just another place to be unhappy.
Some people love Sosua, some people do not, but the least anyone could say is that Sosua is absolutely unique.