I'm sure some of you guys have wondered why Cartoon Network stopped titling their original series "Cartoon Cartoons" in 2003. Well, there's a nerdy explanation.
What do most of the Cartoon Cartoons have in common? One, they started off as shorts, and kids voted on whichever one they liked best to become a full series (Ed, Edd n Eddy was the one that wasn't based off a short). Two, the Cartoon cartoons started off as being animated by Hanna-Barbera, then they transferred over to digital animation when H-B was deprecated. They had similar animation styles (again with the exception of EEnE): flat, angular, 60s-esque stuff.
Kids next door was the last Cartoon Cartoon, since that was CN's last original show to be greenlit based on voting results from kids. Shows like Camp Lazlo, Hi Hi Puffy amiyumi, and Class of 3000 had no business being under the Cartoon Cartoon name since those were simply CN original series made from scratch with no Hanna-Barbera connection, and the animation styles had changed.