I've convinced myself they're Up Front's experimental group. They try stuff, and if the concept works, it gets passed on in either distilled or diluted form to Berryz or Juice=Juice.
Having said that, their wildness/tekitou-ness/non-debutable-ness is what makes them adorable in the first place.
Un-debuted, they're getting more singles than any of the H!P groups so maybe best to not complain? These girls have more than 2 full albums worth of original songs under their belt.