The Hatsan Blitz and the Hatsan BullMaster are two of the very few semi-automatic bullpups that are commercially available at this time. The Blitz has the extra coolness factor of having an option to shoot full auto with the flip of a switch and get a lot of shots per fill.
The airgun market wants more choices in this class of airguns, but the airgun manufacturing technology is just not quite there yet for the price point buyers want to spend, and the accuracy and reliability they demand from a semi-auto precharged bullpup.