Methinks it is a supply-driven rather than demand-driven phenomenon. Entrepreneurs look for things that have the greatest possible shock value to increase the appeal of their commodity (old Alexis deTocqueville was right oon target when he commented on the bombastic nature of the Amerikan political discourse).
Ditto for so-called "ordinary people" - they have all been turned into petty capitalists peddling their own personal commodity (sex-appeal, work skills, social status) and wrapping so as to increase their shock value. Hence the popularity of the "jail look", Sports Utility Cars (aka SUCs), goatees and cigars, nazi paraphernalia - in a word, anything that is 'extraordinary' from a conventional point of view. There ain't such as thing as 'negative publicity.' Anything that increases the visibility of commodity goes.
wojtek