Sox, you may be right, but....
A standard shotgun,IN TRAINED COMPETENT HANDS, is an incredibly effective tool for close range defense. The same shotgun can be used for recreation, such as hunting, clay games, action shooting, etc. What you are positing is way more specialized.
And,light weight in a hard kicking HD tool is not an unmixed blessing.
The bullpup design is also not universally liked. The balance point is way far back, and that doesn't aid control.
But, I do think a little more R&D in this area is needed.
