I think dio building has been in this hobby for a long time. K&C always placed their sets in dio form and, we have a good range of dio making materials available and have had for a good few years. Suppose it depends on how one defines diorama. I do see more and more people now having the confidence to post what they do with their sets and, not worrying that they are at such and such's level.
Some people build from the ground up some buy all the products to create a scene but, its good to see that some of the entrenched negative views to dio building, repainting sets and the like have died out. Its a better hobby now that more do this type of work.
Mitch