Interesting, for years and years it's been the "go to" truck configuration. And now, suddenly, someone decides it's unsafe.
Maybe, just maybe, the double or crew works better for a light truck buyer with a family - and needs to hauls stuff in the bed, and have room for the kids - thus the 1500/150 market and dual cabs options.
But, it makes much less sense in the 2500/3500 market as those are working trucks generally - and less likely to appeal to the family set. We RV'ers are a different breed, so have unique needs in hauling more weight, but would bet we are the lesser buyers in the truck markets, and most 2500/3500 trucks appear in working positions - farms, ranches, heavy construction. So the space behind the seat is more for storage than kids in that market. Most don't take the kids to works with them.