Several factors are in play here. A good story and poser lighting is all thats really needed. Look at the movie Ice Age. That didn't use high end hdri lighting. Our character development is sufficently high enought to make great movies too.

The poser community is diverse and fractured. Few have the modeling skills to make and rig quality characters. Think about it- NO STORY has a complete set of characters. 
Little red ridding hood for example. Sure, you could search for months and maby find "some' of what you need. (at great cost) But it'll be unlikely that you'll find everything you need (characters).

Poser is an animators tool. So it's an end user tool. No story 'groups' of charactors and props, limited motion files, no  music and background sounds and no specific stories for the existing characters. And it's all done by individuales

Does this make sence?