I was introduced through (YOU GUESSED IT!) The Basic Moldvay-edited basic D&D with the Erol Otus "Fighter w/spear and mage w/torch fighting a Dragon" on the cover. I bought it in a Circus World in 1981 and read it myself - my first exposure to D&D.
Later, I learned to really play (get "good" at it) from playing with newfound high-school friends in the late 80's. Until that time, I DM'ed with one to three players, and used every structure from dice rolling to freeform story-play to determine combats and luck.
The problem now is that there's nothing like that basic box set on the market. To explain further, at the time, the only competition were traditional toys and video games. Video games (atari and coleco, mostly) were in their infancy, and expensive to play. traditional toys were cool, but limiting (usually there were set rules that allowed little variation). RPGs were a totally new medium that allowed guidelines for story-based play that I had been engaging in for years, and its versatility couldn't be beaten by space invaders, or defender, or donkey kong. There was noother toy quite like it.
Now, set-top and PC games are hugely variable, more than the average kid needs it to be, anyway, and there is lots of choice, AND you can wait a year and the $50.00 game becomes $20 or $10. With RPGs, the book costs hover between $20 and $40, and have a hard time competing with the visual feasts of electronic games.
What hobby gaming needs is an inexspensive medium so original, so different that there is literally nothing like it in order to capture minds again without the need for other players to show it. And no, I don't know the answer, or I'd be a millionaire.