I agree that complication is a factor - I couldn't imagine a new gamer picking up 4e, for example (in either PHB or Essentials form). And if I had to introduce a new RPGer, I would definitely build that person's PC, using their descriptions of a fantasy flavoured paragraph to guide my mechanical decision-making.
But I also think that Hussar has a very good point. 20 to 30 years ago, RPGs were a good way to experience the thrill of a first-person adventure game with combat and exploration elements. Fighting Fantasy Gamebooks flourished around the same time. But who, now, would pick up a FFG rather than a computer game? (Well, I would, because I don't play computer games, but I think that puts me in a pretty atypical category.)
For me, the main thing that RPGs offer is the opportunity of moving beyond
merely exploratory play, and playing a game where the participants can actively build a world and shape a story that says something that they want to say. But as I said on
this thread, with 4e WotC have built a game that offers this opportunity only to those who also love the rules crunch of RPGs like Runequest or Rolemaster, or of CCGs. As Pawsplay wittily retorted,
it's as if WotC were trying to recruit Mearls himself.
I wonder how a mechanically completely different RPG, like HeroWars/Quest, would do if it had the brand recognition and market power of a company like WotC? Are there players out there for a non-exploration rules-light RPG? Maybe. Or maybe RPGs, like FFGs, really are a lingering relic of a pre-computer age.