Chuck-
There is a direct correlation between optical zoom and image quality, whether you are talking about camera lenses, binoculars, riflescopes, microscopes or telescopes. You simply get a better quality image with higher power optical lenses because the optics, not the software, brings the image closer to the viewer. The higher the power/magnification, the closer you can get to your subject and the better the image quality.
Megapixels are created digitally and can be manipulated by the software on your camera or your computer to a higher or lower density, but they can't create a better image than what the light passing through the optical lenses created in the first place.
