lately, cartoon network has butchered several good shows. ex: Chowder. i recently saw a newer show, and it was total crap compared to the older ones. and most of the new shows they come out with are crap to start with.
as for Nickelodeon, its pretty much the same. ex: spongebob. newer shows seem to be getting more handicapped-stupid instead of the handicapped-funny it used to be. as with CN, most of their new shows aren't that great to start with.
might as well talk about Boomerang. even though its controlled by CN, they still have good shows like Tom and Jerry(ftw), Dexter's Lab, powerpuff girls, etc. they even have really old cartoons which are different that the crap 'toons they have today.
tl'dr: CN and Nick are getting crappier.