A higher attenuator so the finish is drier and not sweeter... makes sense if someone prefers a dry beer. Not sure if their beers suffer from cloudiness but most kolsch yeasts will eventually drop out.
These beers are all hazy hoppy ones so the cloudiness does not matter. In reality, with the modern hops having a sweetness of their own the high attenuation would help the beer be less cloying... IMO.