Don't think its so much the mp size as the quality and sensitivity of the internals, but above that is the need for light.
If the lens is a tiny tiny pinhole, no camera can do a good job, not even the human eye.
Expensive high quality camera's have very large lenses to capitalize on the leverage of having plenty of light which in turn gives grace to have other options too without suffering.
The Inc lens is much larger than the moto.
Whether dealing with binoculars, telescopes, or cameras... they all need light to process an image and do it well... the darker the scene, the more critical.
The larger MP cameras will have better and more sensitive internals which indeed do help, and that alone would help the moto a tiny bit... but I really think the biggest killer "In a bad way" for the moto or any camera phone is the size of the optical lens.... everything else is dependent upon and falls under that.
Manufacturers have to decide.. "whats cheaper"... better internals or larger lenses?....Large lenses are much harder to make but due to mass of product, but mostly because there is more room for error on a larger surface.... technology is so cheap now, its probably a stronger temptation for manufacturers to put in quality internals to make up for the crappy lenses... I prefer a moderate amount of both.
As a very small example.. think of a tiny pair of pocket binoculars.... We will let the binoculars be the lenses and your eyes and brain can be the electronics that process the light....
in full sun bright lighting, the pocket binos practically look as good as a 50mm pair, but let it get dusk or even dark and the 50mm make all the difference in the world, both to see image detail, composition, and contrast, as well as hope to get excellent color reproduction..... its the same with cameras.
