I have the impression that the more miniature the model, the more obsessive the modeler becomes about detail. Look at what some of the scratch-building plastic modelers do. And there are good reasons for this. If a 1/3 scale model has the very same "level" of detail as a 1/6 scale model (for example, both have rib stitching, both have the same cockpit details, both have the same detail in a dummy engine), the 1/3 scale model will end up appear "barer" than the 1/6 scale model. So to make the detail of the 1/3 scale model look as "visually dense" as the 1/6 scale model it probably needs 3 or 4 times as much detail. Remember, tfokker's 1/2 scale DVIII? Of for that matter his DrI or DVII? But that is a tremendous amount of work and most modelers just aren't up to it. I'm not. There just aren't many Pete McDurmotts in the world.

That having been said, there are always going to be models with more or less detail at every scale.