I feel like "it's so bad it's good" is reserved for movies like The Room where the people involved were making a serious attempt to make a good movie. Kung Pow on the other hand was designed to be incredibly stupid humor. It is literally pieced together from old crappy kung fu movies the voices are intentionally misdubbed, etc. It's supposed to make you laugh about how stupid and cheap it is, and it succeeds. That's the joke. You're laughing because they did exactly what they set out to do.
Ok, I see your point. The makers of Kung Pow deliberately made a farce of a movie, it was never serious.
Thus, my new admission to this thread is: 10 Cloverfield Lane. The makers tried to make a serious movie and they failed. That movie was laughably bad...especially the ending.