Among people who are actually into drawing, photography etc, human body is much less of a taboo. For example, to just shoot a basic portrait pleasant enough to hang on the wall, one needs to consider subject's gender, age, body shape and skin tone - for his or her own enjoyment of your work. In the same way, I would imagine you have to first draw buttocks to eventually proceduraly draw a passable clothed person, which has many important applications in art, gaming and even education, medicine, ergonomic design...