Its not like you are switcing lenses, like on an DSLR camera. Its not a "lens" that determines megapixels. Its a whole camera module. Changing the module wouldn't do jack, since the tablet would not have the drivers for a different camera module to function.
But I understand the frustration. Manufacturers constantly cheap out and use crappy cameras on tablets. Its not my primary camera by any means (even for taking spur of the moment snapshots). But on a device like the Note 8 (a portable note taking tablet), I could see how the camera has a lot of utilitarian purpose. Such as for inserting photos into work notes.
