Hey she's right, Joe Public.
Go ask them at CGTalk, and see what they say.

To go with your barbie doll analogy, you can model a completely totally anatomically correct, perfect human and take a picture of it in a studio and if the materials used aren't as equally accurate, it just doesn't look real.

Digital artists struggle constantly with making human renders look right, even with the best physical models possible. The reason is our brains know the subtle differences between surfaces, based on thier physical properties. The hard part is making a bunch of polygons look convincing, and shape has little to do with it. Surface properties have nearly everything to do with it.