Everyone goes through phases in life and being able to explore them fully allows people to move on instead of being stunted in place.
Few things are more intriguing than the opposite sex and sexuality, the fact that it's 'the oldest profession' should've legitimized it by now. At least people have an outlet to explore their desires even if it's perceived as being shady.
I've had nothing but fun myself and it's helped me get over a few insecurities.
Shades of Grey > Black/White