Why don't Mature Comics/Animation have as much of a legacy in the U.S as France/Japan?

[WindowPhil]

Disclaimer: If I'm wrong, then I'm wrong. I'm not French or Japanese. But my knowledge of Comics and Animation has given me this impression and I'm going off of it.

From my understanding, I'm under the impression that the of the 3 comic powerhouses (U.S, France, Japan), the United States has a legacy of a more age segregated view of comics/animation than France (and by extension Europe) and Japan (and by extension Asia).

In Japan, you have a whole bunch of Anime and Manga that cover a wide variety of more mature and nuanced topics. This is obvious, as we have seen them have a wide popularity in much of the world among a niche group of young people.

In France, Bandes Dessinées (what the French call what Americans call comics and Graphic Novels) are referred to by some as the "9th art" (the first 8 are Architecture, Sculpture, Painting, Music, Dance, Poetry, Film and Television). France is also the largest market for Anime and Manga outside of Japan.

In America, you have animation and comics (aside from a few outliers like the Flintstones) until recently being thought of as exclusively a "kids thing". Until the 1990s with the beginning of shows like the Simpsons, Animation was synonymous with "low quality Saturday Morning Cartoons". Kids read superhero comics and watched Saturday morning cartoons, and abandoned them as soon as they aged out of them. The Comic Code Authority was established in the 1950s to censor comics, and that was based around a presupposition that it was only children who could possibly enjoy comics and therefore things like violence and substance use need to be cracked down upon in them. That same presupposition also existed in animation. Both weren't (and still aren't to a large degree) seen as a legitimate art form like in France or Japan.

Of course this has all changed somewhat in recent years with the rise of Adult animated comedies, American consumption of Anime, and the current wave of Superhero Movies and TV shows. But it's definitely not as culturally established as in France or Japan and you can see the underlying mentality continue (IE: "Look at my new graphic novel." followed by someone saying "That's not a novel, that's a comic book.").

So what's the deal? Why don't Americans have as nuanced of a view on Comics and Animation as the French and Japanese?