Is Alexander Kluge to film what John Cage is to music?: i.e. all art is potential material for film, just as all sound is potential content for composition, as long as they are drawn from Art and Music respectively.
That is; while pretending to be non-discriminatory, they both in fact still retain a distinction between what counts and doesn’t. (Although I don’t know to what extent Kluge makes this claim. It is just that his films appear to be all-inclusive, while in fact (as far as I know) they are highly intellectualistic and do not feature references of any interest to pop culture).