The last sentence means that Rugers have a quality issue with their shotguns, no matter what their fans of handguns think. Their casting process, it seems, does not give them the tight tolerances on a regular repeat basis to build a quality over-under.
They open WAY too easily, meaning they are not that tightly built.
Nothing wrong with 15K shotguns, although you could have bought CSMC's A-10 for about 4K in preproduction - now they will cost about 8K. A takeoff of the Beretta SO style, they are getting rave reviews