Quote -
A mesh is nothing more then a wire to hang a good texture on.

This I think is far from the truth, depending on the lighting conditions of the render.

If your model is only ever going to be lit very brightly with little or no directional illumination, you can probably get away with doing nothing with the underlying mesh shapes and rely upon the diffuse texture.
But IMO in all other lighting states the lack of a good morph will, to a greater or lesser extent, break down the illusion that the diffuse texture alone gives.
With Apple_UK's example, try lighting the unmorphed figure with a single spot and from one side - the diffuse texture on it's own will struggle to carry the illusion of an older character (unless there is also a displacement map at work).

 

PoserPro2014(Sr4), Win7 x64, display units set to inches.

                                      www.danielroseartnew.weebly.com