Noisms has some interesting things to say about selling RPGs to kids today, commenting on some points Trollsmyth made on the same topic in a post on Mishlergate. They're both largely right, I think. I got into D&D with 3e when I was in middle school, but I was a kid who'd wanted to play D&D, and D&D specifically, since 4th grade. That's not usual. The group I play with at college is almost entirely composed of people who hadn't played RPGs at all before I met them, because even though they're all Grade-A RPGer material, they either never realized what RPGs actually are, or got intimidated out of trying them on their own. The industry doesn't reach a lot of potential players.
But that's partly reasonable of the industry. Though most of the people I knew in high school were perfectly able to spend the money to buy RPG books, most of them didn't. Why? Sometimes, it was because they'd rather spend that money on computer games or manga, both of which are much more expensive hobbies than RPGs if you're into them on the level that these people were.
But mostly, it was because they didn't see anything wrong with downloading PDFs illegally rather than buying books, and why spend $30 on something you could get for free? I can't generalize outside of the people I personally knew in high school (and know in college) but most of them didn't see PDFs as valuable. Either they didn't understand the work that went into them, or they didn't care. Likewise, they didn't understand the work that goes into distributing and marketing a product, so even if they did recognize that they were ripping someone off by downloading a PDF (or an mp3 file, or a movie, or a video game . . .) without paying for it, they just figured the main person they were hurting was "the company," which wasn't doing anything useful or properly compensating the artists to begin with.
So I can understand why a company wouldn't be interested in marketing their stuff to teenagers.
On the other hand, I won't deny that there's plenty of foot-shooting going on. The big issue is that companies are still making games for boys. But that's another post entirely.
(And note that, for the most part, I think my generation has a lot more good qualities than it's critics give us credit for. We vote, for one, and we've got pretty impressive volunteering and service numbers. But, for whatever reason, a lot of us do have this one obnoxious blind spot.)