Funny, because from the first 10 episodes of Avengers Assemble that watched, i think EMH was a better way to get kids interested in the movies and the comics, not only did they take the essential stuff and adapt the important stories, but it also felt a bit like the movies in some places.
It also did some of the things the 90s X-Men cartoon did well, which was serving as an introduction for the comics, watching the show you wouldn't need to read the 60s-70s Avengers comics in order to know what was going on, i think comic book cartoons should do that more often, it reminds me of anime adaptations of mangas, but with 50+ years of stories, the animation studios are able to trim up the fat and only go with the characters and situations that are necessary.
It's a near flawless business module for cartoon adaptations, since it benefits the comic sales also, then as the show goes on, it can start adapting more modern storylines too, the X-Men 90s cartoon for example was pretty much running alongside the comics and i think that did help the sales.
I know they wanted to push for a Marvel Animated Universe, but it would have been better for most if they had used EMH as the center of it, instead of Ultimate Spider-Man, which has been criticaly hated since the very moment it premiered.