Wow, you started this discussion TWICE before and both times you were shot down, There are MANY Japanese cartoons that are super simple, and many western animated shows that are detailed.
Name me one modern American cartoon that has fluid, detailed
2D animation and character designs like the old cartoons from the 1940's.
The only shows I can think of are
Animaniacs,
Ren and Stimpy (the original series on Nick),
The Boondocks and
Avatar: The Last Airbender, and those last two shows both mimic Japanese animation.
I can name you plenty of Japanese animated shows that have high production values (rivaling animated movies in some cases).
Naruto
Samurai ChamplooBleach
Trigun
Trinity Blood
Full Metal Alchemist
Afro Samuraietc. etc. etc.
Face it, the Japanese have higher standards of quality with their 2D animation. Most American cartoons are slapped together to appease the legions of kids that are glued to Cartoon Network and Nickelodeon.