It just seems as far as money/major labels are concerned, musical content seems to have a pattern that follows in every single musical genre. I think of all this as sort of a sawtooth theory in which music can become so big in popularity that it loses itself and the bubble bursts/start from scratch with something else and pull it from the underground. Rinse and repeat. Genres rise and indie labels take a hold of that style, afterwards the majors see potential. Everything that follows, that style or genre is milked as much as it can, almost seemingly to the point of desperation. History seems to repeat itself in that was as well. I've noticed this recently with hip-hop for example. If you take a look at the beginning and where it is now, it just seems like the decades were a segue to something more "trashed" within the style and going downhill etc..