Jim, it's an interesting and well-conceived argument in my opinion. I don't think it is true if you say, D&D is only a horror game. Then again as many others have pointed out it is silly to say it has no horror elements and horror is in many cases a perceptual matter in the eyes of the beholder (not that Beholder, who is certainly horrible, but the beholder beholding the encounter).
It is certainly a mythological and psychological as well as a literary and gaming argument. I think what you are saying (and you cna correct me if I'm off-base) is that by all historical accounts most people before our age would have considered monsters, horrible environments, vicious death, risking life and limb for unknown, dangerous, and potentially cursed reward as being elements of horror. Nowadays, being jaded to a certain extent, and with literature and other forms of media splitting into such small, self-contained, and heavily encapsulated "genre specialties, it is hard for many people to see horror unless it fulfills a certain prescribed and proscribed equation of X, Y, and Z. (If you're missing Y then it isn't really horror, it is the sub-branch specialty of fantasy game horror, but not fantasy video game horror. That's another branch of specialization altogether. And modern man is nothing if not obsessively techno-specialized. Which is kinda ironic in the gaming community, because fantasy is about reducing things to their most basic and primal elements in many ways, and yet there is that strain within the game that is heavily concerned with great minutia. Fantasy is about magic and scary creatures and the unknown, and fantasy gaming is about controlling the best math stats through your racial and power attributes. Fantasy is about encountering the unknown and magic mysteriously creating the impossible, and fantasy gaming is about knowing all your monster types in the Monster Manual and magic being as tightly controlled as if it were the province of an electrical engineer or an IT administrator. It's a weird juxtapositioning of contradictory concerns.) But I think it is safe to say that most of our ancestors would recognize monsters as being de facto elements of horror, whereas many of us see them as "combat obstacles." Familiarity often breeds a reorganization of what we think we are perceiving into a sort of prejudiced assumption concerning what we already are sure we know about.
However as a man who has been ambushed on occasion I can tell you without any fear of contradiction that situations like that, and the game is filled with them, are indeed horrific. If being ambushed by a monster or crushed to death while infiltrating a dangerous environment wouldn't really give you the willies then you aren't doing it right.
Then again when you are really in fear of your life and the life of your companions that invokes a certain kind of feeling of horror, while doing the same thing in your imagination at a table while eating corn ships, drinking beer, and cracking wise about the danger posed by the red-eyed goblin horde invokes a whole nuther set of feelings and responses.
Depending then on how you go about it a monster can be a manifestation of all that is weird and scary, or a monster can be the funny looking obstacle you gotta kill to get at the Ruby Rod of Rumplestilkskin.
So I think a lot of this is "worldview." I just don't think people's imaginations work nearly as well as they once did when it comes to associating emotional responses to potential outcomes. Especially where danger is concerned. We've got an explanation and an out for everything. We've seen too many movies where Spock gets reincarnated, and played in too many games where resurrection is just a potion or a spell away. It's hard to scare people who think of virtual reality death and killing in video and role play games as more fun but less scary than a roller-coaster ride.
Nearly all of my ancestors would have considered ghosts and goblins and monsters scary. Very scary.
However being used to them in game as a natural part of the background environment I might consider them just interesting tactical challenges.
Iffin though I had to fight a real monster in the real world, something like a Beowulf against Grendel then you can just bet your bottom dollar to a bag of doughnuts I'd go in really well prepared and scared to a fine pitch of sharpness. If I wasn't sacred then I wouldn't be very sharp and so I'd likely be the one to get sliced up and eaten. And if you've never seen anything eaten alive then belief me, it looks kinda scary on most occasions. And yeah, in real life you get used to things too. So that things that once spooked ya (like dismemberments and decapitations) are old hat and not that much to pay attention too. However there are still always situations you can walk into that if you aren't scared then that's just because you're a fool, or already dead. And I think that most modern people just lack the imagination for real danger, fear, and horror anymore. They don't face those kinda things enough for it to seem "real" to em, even in their own minds. But not all that long ago many of your ancestors faced that kinda thing constantly. So to them horror was not being spooked in a dark movie theatre by an imanagnary scene, it was the difference between being cautious and being dead. And I think to some extent the game is losing that sense of the wonder and reality of fear as rapidly as is modern society.
I will say this without any doubt in my own mind. The older versions of the game were a lot scarier than the present versions of the game. I can't say exactly why, though I have my own theories, but 3rd and 4th edition don't strike me as scary at all.
