TaiChara tells the truth, Mercurius, about what's going on. Kids (and other people, too) are grooving on the collaborative, socially mediated construction of story-telling games.
It's "the other" direction of development from MUD, not the one that gets you EverQuest and World of Warcraft.
This is an old problem in the FRP business. The latter may well turn out to have thrived on a "generation" that in the long run is not the rule but the exception.
The first generation did their own thing and made it up as they went along. (I could say "we", as that's the scene to which I was introduced and the ethos that still seems natural to me.)
Besides there not being another option if they were to play the games that had yet to be created, they saw making them as part of the fun.
Gary Gygax was glad to let Judges Guild have a license to produce supplements because he didn't think there would be much of a market for them. After all -- to the minds of the early fantasy gamers -- making up that stuff was part of the fun. It would be like paying someone else to go eat the candy one had bought for oneself!
He also was not at first (or later) a pusher of conformity. In fact, he wrote a letter to the prominent APA Alarums & Excursions in which he said that conformity would never be TSR's policy so long as he had a say.
Well, as it turned out there was a big market for "have us do more of your imagining for you", and for "conformity in major systems" (and increasingly 'minor' details as well).
Even after the publication of the first four volumes of AD&D, he wrote in The Dragon against the idea that D&Ders should be subject to an endless flood of supplements and revisions demanding purchase to "keep current". He admitted that purely as a business man he relished the prospect -- but also that the pecuniary was not the sum, or even the first, of his values.
He was a game maker (and, more broadly, entertainment producer) by personal vocation, not as a convenience in the "higher" calling of pure capitalism. He was never likely to give it up for commodities or real estate or electronics or software or soda pop.
Now we've had such a scheme for long enough to exert quite a bit of selection pressure on who is into the game and who is not.
That a good portion of those who are not into it happen to be doing their own thing and making it up as they go does not dismay me!