In It's defense, D&D has done a fairly good job at taking advantage of its market leader status, and having its cake and eating it too. D&D has always been very coy with its implied settings... It has always tried to have it both ways. Luckily being the market leader; most players squint or ignore what they want so that they can say that they are playing in their 'unique' setting. But in reality the 'unique' D&D setting = "Parts of D&D I restricted or house-ruled to do what I want, keeping the rest of the base D&D setting and genre assumptions, and calling it 'unique'."
While I take your point that D&D (like all systems) imposes certain shapes and ideas on the games people play with it, I think you're being more than a little excessively strident here. Having things in common, even with every other D&D setting, is not the same as being
effectively equivalent. E.g.,
Shadowrun is very clearly influenced by D&D concepts, but has a substantially different theme, tone, and primary goal than most D&D settings today, hewing closer to the old-school "heist" approach. Then my
Dungeon World game (a PbtA system specifically aiming for the feel its designers remember of old-school D&D) takes inspiration from
Al Qadim, GURPS Arabian Nights, the actual
Thousand and One Nights, the
Rubaiyat of Omar Khayyam, the
Muqaddimah of Abd Ar Rahman bin Muhammed ibn Khaldun, and my (limited) knowledge of the Islamic Golden Age and Al-Andalus: monotheism, genies, political intrigue, financial motivation, saving face being sometimes more important than combat victory...
You can still do a lot, and still have
actually unique settings. Just because there are structural similarities doesn't mean they aren't unique. Broccoli, cauliflower, cabbage, mustard seed, and turnip are all from closely-related
brassica species (the first four are all the
same species,
brassica oleracea), but I'd call broccoli and cabbage unique vegetables nonetheless. I mean, with one you eat the leaves, and another you eat the unbloomed flower buds!
D&D is not 'generic fantasy' by any measure. It has been and always will be its own style of 'D&D fantasy'.
I have to agree with the above poster that I'd call it "heroic fantasy" rather than narrowly "D&D fantasy." "D&D fantasy" IS a thing, and it's had a huge influence on (for example) the MMO genre. But even games
heavily influenced by D&D, such as Final Fantasy, can end up somewhere pretty radically different despite sharing that common root. FFXIV, a game I play frequently, has a cosmology that would never work in a D&D system, and explicitly notes that all forms of combat discipline, including the "purely physical" classes like Monk and Warrior, manipulate aether (="do magic") in order to function, they just do so by channeling that aether through their own bodies, rather than into external collections of magic. And even "pure magic" classes sometimes do the same, e.g. Black Mage has to carefully spool up fire-aspected aether (fire magic) inside their own bodies before deploying it--a small mistake can potentially kill the user, burning them from the inside out. (The player character is protected by their "job stone," the soul crystal that you use to learn how to be a Black Mage.)
But as in my reply to King barber, TSR and now WOTC D&D has done a fairly good job of selling 'D&D Fantasy' = 'Generic Fantasy'.
I don't think it's all on their shoulders. Tolkien basically rewrote the book on fantasy settings. He didn't
mean to, mind; he was just very serious about world-building and really making
use of his knowledge as an expert on Anglo-Saxon literature. (His
Beowulf translation is still fairly authoritative, as I understand it.)
The fact is that the game tropes of D&D have been so influential on the fantasy genre that D&D forms many people perceptions of what fantasy is. So to many people 'D&D Fantasy' does = 'Generic Fantasy'!
It makes for a nice self reinforcing feedback loop that has allowed D&D to have it both ways for decades now.
Well, let's be real. "Generic Fantasy" is probably a phantom to begin with anyway. That is, what could ever qualify? "Fantasy" literally means "imagination unrestricted by reality" or "imagination, especially when extravagant and unrestrained." "Generic Fantasy" would literally just be "whatever you can come up with." Nothing that
has a context can ever be "Generic Fantasy."
So when people speak about a "generic fantasy setting," they're implicitly talking about something embedded in a context. In this case, "a fantasy setting in which role-playing a character is well-supported." That's still pretty broad, and I'd still grant that D&D narrows things further than that...but not so much further as to be radically excluding huge parts of that shared context. Now, I find that a lot of
players artificially limit even what D&D actually does provide access to (and then many of them try to present this as "true" D&D or as "actually" generic, when truly it's just "the stuff I grew up with, so its assumptions dissolve into the background rather than seeming aggressively brought to the surface.")
This is an interesting point. Before DnD got truly huge, it still had influence on the fantasy genre by, through game developers that played, having a huge influence on the design and assumptions in countless Fantasy video games that were (and are) played by tens of millions of people, shaping how people see fantasy even if only 1/1000 of the people who played those video games actually played old DnD.
I mean, while that's fair, D&D "got truly huge" in the 80s. The early to mid 80s is when we had the D&D cartoon, for example, which reached millions of people even if they didn't play the game. A lot of the people who played D&D in the early 80s were out of college no later than the late 90s, and that's when you started seeing the profusion of MMOs, which are pretty clearly one of D&D's two biggest impacts on video gaming as a medium (the other being single-player RPGs). I fully grant that you can see D&D's influence at least as early as 1987, with
Final Fantasy, but...well, video gaming in general had only had two generations of consoles at that point, and PC gaming itself was still in its infancy.
More or less, I'm saying there really weren't
that many video games that
pre-date D&D getting "truly huge." D&D looms so large over the market in large part because its boom-times were literally right at a formative juncture for video gaming, and then that boom time heavily influenced a whole generation of story-heavy, mechanically-heavy gaming experiences. (There had been classic Adventure games before that, but RPGs took those in a new direction, marrying in elements of action and statistical improvement that have become core traits of CRPGs today.)
For goodness' sake,
Pong as a home-playable game didn't come out until the mid to late 70s--and indeed it was originally proposed within Atari
the same year D&D was published. So....yeah. D&D got big at almost exactly the same time video games got their act back together (after the crash of '83). And that timing could not possibly have been better for centralizing D&D concepts into the video gaming sphere.