I see what you are saying but I think the above is the fact that because of the slump the Comic book marked is in no one really wants to experiment. Even the RPG suppliment GURPS Supers fell into the above pattern - heroes emerge during WWII, McCarthy and the HoUA cripples them during much of the 50's the 60's sees a rebirth and so on.
Do people buy a game series because you’d get a “store brand” version of the Big Two Universes? Maybe. At least the way I figure it, if I’m going to have a Brand X Superman, I might as well have him be the ACTUAL Superman!
Well, true except for the pre-Crisis Earth-One anyway, which depending on which decade one views Superboy as having debuted in, didn't have any superheroes during World War II...
True, but not ENTIRELY true. Nightwing pointed out that BRAVE AND THE BOLD had the Earth-1 Manhunter active on Earth-1 at the same time as his Earth-2 counterpart - making him the one World War II hero active at the same time on both earths. Also, Superboy’s early adventures are set clearly in the 1930s, at least at the beginning; like the Marvel Heroes, the date of Superboy’s adventures have “slid” further and further up as time went on. In one of the two-parters for SUPERBOY AND THE LEGION OF SUPER-HEROES (the one right after they fight Grimbor the Chainsman) the Legion returns to the era Superboy lived in, and it was clearly the 1960s, down to the black and white televisions and underground nuclear testing.
The look, feel and staple accessories of superhero comics -- sleek spaceships, outlandish costumes, ray guns -- were created during the 1940s, and have a sort of late Art Nouveau quality, so it makes sense that, when creating a superhero-populated universe, you sort of feel obliged to explain this by imputing its origins to that period. True, this may impose certain artistic restrictions on the genre; it's just a difficult thing to shake off.
This may be the most direct explanation for the phenomenon, although ray guns and rocketships were around from 1900-1960. Just the same, the World War II period seems to be the Locus for all superhero activities.
The 1930s Art Deco aesthetic is absolutely wonderful (it’s part of what makes TOM STRONG so much fun) and the patriotic “beat back the devil” directness and flag waiving of the 1940s equally so, however, superheroes are so broad that they can work with many kids of visual aesthetics, styles, and times. Lots of great superhero stuff, for example, was done with a distinct 60s counterculture vibe: Ditko’s DR. STRANGE, Jack Kirby’s JIMMY OLSEN and FOREVER PEOPLE, the AVENGERS issues that have Captain America reading Tolkien and saying “far out.”
In a way, the superhero is a sort of metaphor for the atom bomb: a very powerful thing that can change the world.
Someone once said that the world would be more different the FEWER superpowered beings there are, and the more like ours the MORE there are. The reason the Watchmen world is so different from our own is because there’s only one Doctor Manhattan. On the other hand, the reason the Marvel Universe is so much like our own, Viking Gods and Russian super-monkeys notwithstanding, is that there’s a Charles Xavier to block Magneto’s objectives, and vice-versa.
The people he works with and fights are not unusual -- they're a normal part of his world, one that's been around over a millennium.
The idea that what defines superheroes is that they are special and not a normalized a part of the way the world works that society takes into account, may not necessarily be the definition of a superhero. Some interesting work is left to be done involving a setting where superheroes and the superpowered are incorporated into a setting: the fact that superheroes exist changes how the world works, in a more profound ways than the Big Two universes.
One of the things that was most interesting and innovative things about the Silver Age Green Lantern is that he is a “cog in a vast machine,” as the DC Encyclopedia put it, someone whose superheroism is incorporated into worldbuilding: the Guardians, the other Green Lanterns, and so on.
I don't think that says anything particularly narrow about the superhero genre -- the only reason, to my mind, to think of ARROWSMITH as a superhero story is that it's a comic book, which makes the association closer.
Interesting point, that medium does play a role in classification. If Roger Zelazny’s LORD OF LIGHT or E.E. Smith’s Lensman books was anything other than prose novels – a movie, television show, a comic book, they would probably be called “superhero” due to the superpowered, confident protagonists and monsters.