Creator Backlash: John has actually been pretty critical of his early work, particularly on Mighty Mouse: TNA and Ren and Stimpy. He even warns his fans to not study his cartoons, but rather all of his influences--"For everything I did right, there were a ton of mistakes."
He also refused to give himself credit for his directorial role on the Ren and Stimpy episode Nurse Stimpy. He thought it was so bad that he credited himself as "Raymond Spum" instead, out of embarrassment.
He also disliked how he was forced to add strong adult themes to Ren and Stimpy: Adult Party Cartoon.
He also claims that he can barely watch The Ripping Friends, since the whole show was meddled with to death.
Doing It for the Art: The whole reason John became a cartoonist was to bring back cartoony animation to the mainstream and put a stop to the stiff, formulaic TV animation coming out around the time, as well as create Spumco as the only other safe haven besides TMS and Studio Ghibli for cartoonists.