There's a lot of different things at work here, though I think for the first time I'm taking this '3e is too gamist!' complaint as more than just the grousing of grognards.
First of all, it's important to note that this is the mood of players and DM's, not of the game system itself. There's nothing really peculiar about 3e that *makes* you play in that gamist style. There's nothing that enables it or really encourages it, beyond perhaps that the rules assume you're using minis (and even that can be debated -- minis are older than D&D itself, and every edition as availed us of their usefulness). Now, the important thing is that there's nothing in 3e that *discourages* it, either. The rules are clear, concise, easy to use, with a recordable cost and nifty ways to handle complex issues. This is one of the greatest things about 3e D&D, but it has borne with it some tendancies that aren't for everyone. Obviously, 3e has benefited from people with actual game design degrees, who knew mathematics, who knew reward systems, who could keep people playing by giving a ruleset that rewarded you for doing well. This streamlined ruleset is so easy to use, it sometimes implies a lack of complexity, which is not something that is for every game. Witness the "magic shop" debate. The special feeling or complex action vs. the simplicity of simply being able to cast
magic missile once more in a day.
Now, the reason 3e went with a solid ruleset and didn't elaborate much is because of one of the main complaints with 2e: it stifled creativity. It told you how things had to be. It limited you, provided no wiggle room, and said "you play the game like this, or you're playing it outside of the norm." Of course, in an environment like that, with a rules system so full of holes, 2e was pretty much played outside the norm as the norm. Almost no one used the RAW, which means many had complex house rules.
When 3e was made, it was made for the 2e audience...those people complaining about those restrictions that were in many cases purely for story purposes. So the designers focused on the game, on making the thing playable, assuming that the wildly creative D&D audience could fill the gaps they left in story and design. It was their job to figure out a universal cost for a scroll, it was the DM's job to hang flavor on that, to describe exotic ingredients, to dictate where one could obtain such a thing, etc, etc. It was intentionally modular, simplistic, and elegant. It was a skeleton, and you could do the story yourself. Enough people in 2e proved that they didn't need the game designers telling them how to capture flavor...they could do it themselves. What the 2e audience needed was a coherent ruleset.
Now, 3e had the fortune (good or bad is up to individual judgement) to come along at a time when the computer gaming industry was just hitting it's stride. Computer games have a long tradition of RPG's, often with loosely based D&D rip-offs among them (tell me that the "Mind Flare" from early Final Fantasy isn't just a rip-off of the Illithid, and I'll smack you with a strategy guide!). 3e certainly benefited from looking at the approaches that electronic game designers were using...magic items with costs, a process for determining the challenge of monsters, features that you could choose as you leveled up independant of race and class. A modular nature -- every new book is an expansion pack. These are rules elements...many videogames don't really explain them much, because they don't have to. You don't wonder why the merchant is in the dungeon selling potions because you're in the dungeon and you need the potions. It's obvious that the save point is before a boss battle. These elements are accepted in the electronic game because they facilitate fun game play....and they do the same thing in D&D....the only problem is that D&D, as a more creative excersise, demands that these inexplicable things are explained.
Or not. See, with 3e, people no longer *need* complex stories, plots, epic journeys, intricate relationships....it's fluff. It's superfluous to a game of D&D. That doesn't mean it's not important to some people, just that it is unnessecary. D&D can be played perfectly easily as another style of RPG, because the rules system works so well that it's as invisible as the binary that programs the latest polygonal wonder. In 2e, the game largely mandated that you have story...you were a bad player if you didn't. In 3e, you're perfectly fine to be out in the open and not give a crap about how your level 5 half-orc barbarian reached level 5, got to the dungeon, and cared about the treasure in the first place. That, plus the popularity of some nonsensical things in videogames, have lead to people playing purely for the enjoyment of the game, no story, no plot, no relationship, just *playing*. It's accepted by D&D, and it's reinforced by what they enjoy when not playing D&D. It's purely metagame, and it's A-OK.
Which has lead in some cases to increasing divide between those who need a good story, and those who need a good attack roll. There have always been extremists at either end, but the just-playing-a-game crowd is growing to be the mainstream, rather than fringe munchkins who ruin the experience for everyone. Indeed, those insisting on intricate story may be the ones who ruin the experience now.
I'm firmly in the tell-a-story camp. I wouldn't be happy on a dungeon crawl, and I wouldn't like to play with people who are power-players first (though a little bit is always encouraged.

). But I'm also interested enough in the game itself to make knowledge checks = monster entries a cool idea to me. I'm interested in ways to make playing the game more exciting and interesting just as I'm interested in discovering ways to make the story I'm telling more exciting and interesting. I like simplification, and I know it's always easier to add complexity than to take it away. Even my games, story-based as they are, thirst for cool power ups (in my case, monster manuals are my vice...I've got an excel spreadsheet with entries for every monster in the MM, MM2, ToH, ToH2, Draconomicon, Planar Handbook, Manual of the Planes, Fiend Folio, Psionics Handbook, Monsers of Faerun...well, you get the idea).
But the two styles are not mutually incompatible. There has to be good gameplay. But once the good gameplay is there, telling a story could be just as interesting, if not more so...and tying a good story into the gameplay (like by giving individualized powers rather than GP or treasure, and tying that into the plot) is always grand.
I'm done musing for now....but though this certainly isn't an edition problem, it probably is a recently growing "problem" for those who lean more heavily into the story of D&D than I do, because the mainstream is becoming those who are perfectly OK without it. I know WotC isn't going to change it...it's up to us, it's up to third parties...without loosing the brisk and easy-to-use rules, make something interesting.
Aaaaaaaaaaaaaaaand go.