Honestly I think the location of Renderosity in the Bible Belt cannot have anything do do with it. I also live in Tennssee, and I will sometimes do nude renders to put with my products on CP. I know many traditional artists here who draw and paint nude people live. Also, I think many of the vendors are not necessarily from this region.

Renderosity allows nudity as long as there is an advisory. I am grateful for this as I will sometimes browse the Internet and peek in at Renderosity over my lunch hour and I work in a setting where school teachers are sometimes present, so it would not look good if I just happened to be bombarded with nude pictures on my screen without warning. The choice to include those seems to be a trend that individual vendors are electing, not something Renderosity has asked them to do.

"People who attempt define what art is or is not, are not artists"---Luminescence