Well here is a good reason: When you are puttin a massive scene with a lot of people interactinc it is better to handle low poly as real people does with its rotographic technics, the real people program works great when you want to make some scenes with alot of people, if you put more than 50 poser models in a scene, I bet that if you don't have an alpha work station, the pc could get hemorroids :) well this is why i think Real people could be usefull.

SAL9000 - Hello Dr. Chandra, Will I've dream?