Crossing Over

I'm fairly into both American and Japanese comics, and there's something that's struck me about them, vis a vis one another. (Nothing against European comics; I just haven't had much exposure.)

Comics from both support a very wide range of storytelling genres and subgenres. Looking just at the geeky/speculative fiction end of things:

Japan: Giant robots, magical girls, super martial artists, transforming heroes, hero teams (sentai), etc.

America: Superheroes, space opera, gothic fantasy, cyberpunk, espionage, etc.

Of course, especially in this day and age, you can see any of those subgenres in either country, but certain genres still predominate in different nations. But I've made an odd observation: English-language comics are way more quick to cross genres.

For instance, looking at Japanese comics, there's practically no chance you'd see a comic that mixes robots, magical girls, and martial arts. Can you imagine a cross between Gundam, Sailor Moon, and/or Dragonball that isn't a parody?

Conversely, in the DC Universe for instance, you have an almost ridiculously huge array of different genres all coexisting: Superman, Princess Amethyst, Angel and the Ape, Sergeant Rock, Swamp Thing, the Phantom Stranger, Hoppy the Marvel Bunny, etc., etc., etc. - just by reading their names you can tell that if there were no shared DC Universe, there's no chance any of them would ever cross over, yet they all still make regular appearances in crossover events.

Why is this? I'd say it's a weird trick of publishing history. DC and Marvel both started out publishing comics that had nothing to do with each other, but with the emergence of the superhero genre we started getting crossovers, crossovers became superhero teams, teams begat shared universes, and by the '70s or '80s almost everything each company had ever published was deemed to have a corner in those universes to themselves in case a modern writer had an idea for them. Nothing like that ever happened in Japan, where almost all comics are self-contained, or maybe part of a single author or franchise's greater universe.

None of this is to say that one is an inherently better set-up than the other... but I have to say, a universe where John Constantine, Claw the Unconquered, and Captain Carrot's Amazing Zoo Crew can rub shoulders is a lot of fun.