It's not so much marketing as inep ude. Remember the GM diesels of the 80's? , Ford was shoving Mazda built diesels in anything they could...and they were terrible engines. Diesels haven't achieved the refinement necessary to be accepted by the populance at large until fairly recently.
I used to own a '82 VW Rabbit Diesel pickup. It would return damned near 45mpg on the highway, but it was the original 98 pound weakling. Passing became an unwelcome game of chicken as I mercilessly flogged that 52hp machine. It was very entertaining tho...you had to drive it like an F1 car just to be able to merge and blend with traffic.
