Is a closed rule set superior to a set of guidelines?
Yes. Especially when that 'closed rule set' is fundamentally flexible enough to be virtually open.
The videogame manufacturers are aware of this fact, which is why there are so many developers out there now seeking to emulate features such as the open-ended gameplay of the last two Grand Theft Auto games and the super-powergaming gameplay that's par for the course in Square Enix' CRPG franchises (such as the world-famous Final Fantasy franchise) and is so prominent in MMORPGs such as Everquest or PC RPGs like Diablo. While there's a lot of talk about dramatic elements and storytelling, all of the relevant experts on the business agree that it's gameplay--not drama--that makes for overall success and creates the iconic games of the industry.
Got it in one. Case in point, one of those CRPG's,
Final Fantasy II, had a great epic storyline about a deposed family and an evil empire and an epic war. But the gameplay was weak -- it relied for character advancement on a 'you get better at what you use' mechanic. Swing a sword, get better at it. Cast a spell, get better at it. Get hit, get better at taking damage. There were inherent flaws in this system, such as spells could only be cast a certain number of times per day (and thus would always lag behind swords and the like, which could be swung indefinately), and that you only got better at evading blows that you dodged (and since your dodging ability started out at 0, it almost never increased). This game suffers because of playability -- it's considered not one of the greats in the series. Similarly,
Final Fantasy VIII was rejected by many because of it's spellcasting system, where the spells you knew were based on the monsters you encountered, and instead of filling up slots or costing points to cast, you just had a certain number of them that you could cast. These
gameplay elements turned people off, despite really solid plots in both games.
Because D&D's following could be better. For all my disagreement with how the game is currently, I still like it and I would like to see it have a larger presence. You see, I'm not convinced we need to keep D&D to ourselves, only letting others in if they pass the test. This could be a more open hobby, and I intend to help open it up.
I think the main things keeping D&D from being accepted by everyone is that, fundamentally, it requires people to sit in a room with little motion for 4+ hours, at least once a week. This is a time dedication, and a lot of inaction, simply for imagining yourself as Billy Badass in someone else's story. Something like Scrabble doesn't do that, and so it's more popular -- it's more approachable. Those who want more dramatics in their D&D aren't a big section of the market, or the designers of 3e would've followed in their footsteps, rather than designing it as a *game.*