A lot of shows from Canada anymore certainly qualify, not just Johnny Test. Networks gather more Canadian shows since it's cheaper and faster to borrow from them, while managing some of their own like Adventure Time and Steven Universe cost much more to produce. The reason most Canadian animation is hated anymore is because Canadian laws force them to be constantly churned out with very little regard to their actual quality or entertainment value, and due to the fact that the Canadian government is too cheap for traditionally drawn fare, we only get all-CGI cartoons and cartoons made with Adobe Flash. It's very telling that only a few of them made in the last 10 or so years are even remembered, let alone considered decent; the one that comes to most people's minds is Johnny Test, one of the most widely despised cartoons this side of the later Spongebob seasons.
Probably the last show I watched from Canada was "Packages from Planet X", and it was probably one of the most boring cartoons I have seen in recent years. The characters were bland and forgettable, the animation looked wonky and flat, and the plots were the most cliche cartoon plots you could think of at the top of your head, and even my dad said it looked terrible, to which I agreed with him. I actually think this show could be just as bad as Johnny Test, if not worse.
While on the subject of Johnny Test, Regularjosh1 on Youtube said in his Top 10 Worst Cartoons video (fast forward to 7:42 for the part about Johnny Test) that he noticed patterns with the episodes, stating that a lot of the episodes involve the characters competing against each other, and always the same characters every time. That pretty much tells you something about the show...
I've heard of the Paul Dini interview, and I was surprised when I heard about it; it really is one of the biggest problems I have with CN right now is the fact that most of their programming is boys-only-no-girls-allowed and it's what I feel is killing the network, and a lot of the merchandise-driven shows on CN are so blatantly toyetic it's painful.