Fanaelialae
Legend
In other words, while it is true that "gamist narrative elements have often been used", the statement is (based on my experience, and on the texts that became more explicit as it was realized that the game appealed to far more than the initially assumed audience) not a very accurate stereotype or archetype of seminal D&D play.
While I can't say how an "archetypal" D&D group might play, my personal experiences run directly counter to your research. Gamist and narrativist tropes have always had a strong presence in our D&D games.
I'm not saying every group plays this way, or even that it's the "right way" to play (frankly, I don't believe that there is a right way beyond having fun). It is the way my group and some seemingly significant number of others play, and have always played D&D (though some editions support this play style better than others).
4E is pretty close to my ideal of the "perfect edition of D&D" because it supports my play style better than previous editions did. You might argue that it is because earlier editions of D&D were never meant for my play style, but it certainly seemed to work even back then (I just had to bodge the rules harder than I do with 4E; let's face it, a great many groups have house ruled D&D over the years for various reasons related to play style).
IMO, 2nd and earlier editions weren't strongly biased towards any one part of the G/S/N "division". They were what they were (early RPGs). 3.x was designed to be very simulationist, whereas 4E is much more gamist and narrativist. I honestly believe that D&D has room for all three elements, and that all three have shaped it through its birth and evolution. I'm not saying that 4E is the epitome of D&D. Just one incarnation in the evolution thereof.