tendo, not really. There are many comics that are simple and many cartoons that are detailed. Plus, it's a lot easier to draw a comic than a cartoon (as a cartoon requires a lot more effort than a comic).
Most cartoons produced in America have very simplistic character designs. Look at modern cartoonists like Gennedy Tartakovsky, Craig McCracken, Butch Hartman, Seth McFarlane, etc. It seems the only kind of animation that gets any attention to detail is
CG (Pixar, Dreamworks) and
stop-motion (Tim Burton, Henry Selick).
Contrast this with a majority of Japanese animation, which is highly detailed and has extensive production values put into it.
On the comics front, both American and Japanese comics seem about equal (in terms of production values).