The Show's Infamy
This show is known for its lack of popularity. We will analyze the reasons why that is.
OverexposureA major reason why this series gets as much negative criticism as it does is for its overexposure on Cartoon Network and Teletoon. This show is constantly seen on both networks. This may be due to the show being very cheaply produced; it'll make a profit even with minimal ratings. This seems to be good logictelevision is a business, but a lot of people wonder why they don't just air more popular cartoons with far better ratings.
Poor Choice of CharactersAn issue of paramount importance is the fact that the main character is the annoying younger sibling. Why is Johnny the main character? The show would likely be more popular if this role was filled by someone else like rational Dukey or the quirky but intelligent sisters Mary and Susan, all of whom are far more well-liked than Johnny. The series would benefit by removing Johnny.
Another issue is that the writes waste perfectly good characters. Whatever happened to Janet Nelson Jr.? The writers seem to try and shove Johnny into as many situations as possible, when the series would benefit without the constant wasted characters.
Indeed, almost all episodes include "Johnny" in the title. In short, Johnny himself is a big turn-off for would-be fans.
Derivative PremisesThe show can feel very derivative, with most of its characters and premises borrowed from other, more successful shows. Some say it's Dexter's Laboratory, but gender-swapped and from the perspective of the dimwitted blonde sibling.
Johnny Test also has a lot in common with Jimmy Neutron. Both main characters have similar names (diminutive J-name plus sciency last name), shirts with scientific symbols on them, wild hair, jetpacks, smartwatches, access to labs, intelligent mothers, neurotic fathers, and smart canine companions (though Jimmy's dog is a robot). Both shows begin most episodes with the main character being annoyed with some basic problem, introduce an invention which will inevitably go wrong, and have everything go back to normal by the end of the episode. The main difference is that Johnny isn't the genius; he has his sisters for that. Still, the series is incredibly derivative. Which brings us to...