Of course it wold be nice if Mathematica would serve as a replacement for CAD- and raytracing tools like Maya etc. But I don't think that this is the intention of Mathematica.
On one side, Mathematica is surely about presenting data - but it's strength is not so much "photorealism" but speed, accuracy and flexibility in the presentation of any
kind of data - and not just geometric modelling data.
I think the capabilities of mathematicas 3D-Presentetions are more or less restricted to the capabilities of the GPU (or the graphics drivers respectiveley - e.g. OpenGL). This provides a good graphics performance without slowing down the CPU.
In fact, mathematica is even a bit weak for geometric modeling - it does for example not even provide boolean operators for geometric 3D-primitives like spheres and polyhedra - i really miss that functionality, and it's not that trivial to implement it in Mathematica.
I think the typical use of Mathematica for rendering/animation purposes is to use it as a prototyping-tool. You can work out and modify the geometry fast and flexible within mathematica and export it for use within your rendering tools or directly within your Applications.
The other way around makes sense as well:
Build and render objects in your preferred construction/raytracing tool and export the geometric data to Mathematica e.g. for stress/structural/material analysis, mathematical transformations etc.
Though, I would not mind to have a fast raytracer packed within mathematica...