After the wall fell Germany had serious economic problems propping up its eastern half.
Also, what does one do with such a weapon if there is a misfire (dud round). How do you eject the dud?
As I understand the action, you simply crank the cocking knob once more, and the dud is pushed out the bottom of the weapon.
All in all, it was a promising design, with not a few implications for the future. The caseless ammunition was a true innovation, which could have revolutionized firearms the way smokeless powder did. It probably still will, when someone else takes up the concept.
Such things do not die...they only stay (temporarily) dormant.