I don't know, but I will tell you this: despite demographic information that G rated movies ROUTINELY and OVERWHELMINGLY out-perform PG or R rated movies at the box office, Hollywood deliberately includes "hard" material so as to avoid the social stigma of doing "unsophisticated" movies. Likewise, who has more disposable income, a 19 year old or a 45 year old woman? But where is 80% of the marketing aimed? The 19 year old. Now, part of that, I know, is that the sellers are hoping to "lock in" life-long purchasing habits and brand loyalty. But still, it's the same as your question: why do they market to people who don't have as much financial clout? Because it's hipper, allows them to do more cutesy things in their ads, and gives them cocktail party conversation.
It is curious isn't it? They must have some interesting business models (Such as they are).
Or maybe what many/some of us suspect is true, that is, they have ulterior motives, and uninhibited by any moral values, they charge ahead flinging $HIT everywhere, KNOWING at least some of it will stick. Ahem.