To prove my point on how target a specific crowd can help instead of hurt, let's take a look at the former Fox Kids.
One of the reasons I believed they started declining in ratings was aside from Power Rangers/Galidor, they catered more towards anime/Pokemon fans. Not that their line up was horrible, but again too much of one thing even if it's good can spell trouble.
Take a look at Fox Kids during the early to mid 90s, they had shows that varied in feel:
Live action shows: Power Rangers and Eerie Indiana
Comic book shows: Batman The Animated Series, X-Men, Spider-Man and Silver Surfer and The Tick.
Shows with Looney Tune characters or characters with Looney Tune styled humor: Tazmania, Tiny Toon Adventures and Animaniacs.
Shows with no existing source material: Bobby's World
Shows based on movie: Attack Of The Killer Tomatoes and Casper (yes he's a comic character, but the show is more in tune with the movie.
Anyway, my point was you had a little of something for everyone, or at least there was the attempt.
Now, if cartoons (outside action toons) would explore other setting aside from the schoolyard/neighborhood, then they'd start gaining more interest from viewers.
I mean when you don't take full advantage of a medium then of course it will fall behind the competition. Video games, however, do quite the opposite.