Poser and other graphics apps , like photoshop , are widely used for erotica art or porn. You just have to look at all the sites that offer it up and what they charge for it.  It is true that some sites favor cannabalism and show impaled women being roasted while others show bondage and torture to a degree that would be very expensive to fake. 

 

If you just want two people 'making love' then pay a couple of actors and try not to jiggle the camera while recording. If you want to show the abduction of  some coed, have her gangbanged, have sex with a mutant beast and then get chewed on by a man-eating plant then Poser + is the way to go.

 

The stuff needs to be done fast, and that means fast render times , so high-res textures and complex lighting are not an option. Some of the pay sites though are rendering in 3ds max with vray for some amazing work. I doubt the audience for some of this stuff really cares  as long as they can see the action.  You only need to look at renderotica (and a few other sites) to see the most viewed pics are not always the best technically or artistically.