> If it has to be a freight or logistics/materiel/fuel aircraft for the forces before general service, so be it.
The challenge for that is economic: those use cases which are generally filled with adaptations of older generation aircraft at the moment probably don't pay back the R&D costs of the programme. Especially since a viable civil aircraft programme also involves worldwide line maintenance capability, a liquid aftermarket etc.
Blended wings are are not a novel idea, and the major airframers have produced multiple concepts, often combined with theoretically much more efficient open rotor engines. The first attempt at a blended wing passenger aircraft was actually over 100 years ago (it was years ahead of its time... and it crashed on its first flight). But there are a lot of challenges other than the passenger experience characteristics people have already mentioned: instead of a simple tube, you now have a broad internal space that needs bracing in a way which doesn't add weight or negate space advantages, and novel designs greatly increased uncertainty in an industry whose safety record relies on predictability. And there's commercial conservatism in an industry whose customer base invests billions in new airframes on the expectation of commonality with existing airframes, phased replacements over predictable replacement cycles etc, and where the second entrance to the market sector might well be the most successful....
Military use involves completely different economics, but for related reasons the anticipated greater fuel efficiency is rarely a big deal for the military. Still, if the military write blank checks, that leaves scope for prototypes that airline executives might struggle to say no to