@ Y-Phil Not meant to offend anyone :) I tend to be a little dramatic at times ...

My personal meaning is that allot of artists are very limited on rendering Pinups, but even these are often cut on the legs, guess it would be more work placing them on a floor. Portrait are another thing and sure not easy getting a good eye for a really good Portrait especially in 3D. 

Have you noted? if the 3D Doll got big shiny eyes then she will have big Boobs ( In most cases at least ) so Poser DS 3D artists define the eyes with the Boobs LOL. You can observe this in many cases.

The thing with the cut legs ( Feet ) is not only a phenomenon in Poser . New Disney animation movies have most of the time the Legs cut off , a thing I observed the ones drawd  by hand in times showed more how the animations were walking on the ground . So the Difficult parts in 3D are often just left out by cutting the legs and place a Image shot in the background. 

And sure I understand the Blur out in Poser 3D as if the background is a real Picture and more realistic then the Render of the asset background needs to be blurred to adapt it to the quality of the 3D model ( A possible theory )