Well, long bed diesel would be good for towing even two Airstreams and the motorcycles but it's difficult for everyday driving. We spend months at a time on our trips and much of that time we are disconnected and exploring, everyday driving. Our 1/2 ton Tundra is a nuisance for that purpose.
A great advantage of Airstream is their ease of towing with great aerodynamics, independent suspension, and low center of gravity. It seems to me a tow vehicle for it would have similar advantages.
Everyone's needs are different however.