"Life of Pi" and "Hugo" both had a huge amount of pixels that where not captured in camera. Both DOPs won an Oscar for their work. If more and more of your images are being composited together to make one cohesive image all those artists that brought that image together should be awarded as well.
The traditional director of photography model is broken. Almost all if not all of the images you see on the screen have been manipulated after being captured in camera. Gone are the days of testing and developing a look for a film. Sometimes months before production started the DOP would start testing film stocks and lens with the main actors and actresses. This would make sure that the look that the director wanted could be achieved and that all the lenses would make the face you just paid 20 million for looks as good as it can. After the image was captured there was very little that could be done to fix it. They had to have it right.
Enter Cineon and scanning of film. Things could be fixed well after the image was shot. At first small things. Then the whole look of a film was developed after the fact and digital intermediate became the norm. As digital techniques got better we could do more and more. George Lucas is famous for cutting a actor out of one take and placing him into a completely new one. I will even say these are not split screens, this required lots of artists not in the camera department to achieve.
So if a DOPs job is to light a blue screen and get the key light on the right side of the subject does he/she deserve a credit for images the matte painter makes, or the lighting on the cg tiger, or train station? If you as a DOP only contributed 1/25 of the pixels on the screen then no, I think they do not.
Historically to win a best picure oscar you as a producer had to be able to connect all the department together to make one cohesive world that the audience accepted as real. The tools to do that have changed. The academy needs to start understanding what and how the new tools work and how they add to the film making process.
Right now that cohesive world we want is built in a computer not a camera.
What can we do to change this? It's complicated and involves changing a process is decades old. Answer this question and I bet the visual effects/movie making process as we know it also changes for the better. I am in no way saying that the DOP is not needed or there job is easy. In fact it's is an incredibly hard job, in fact without a DOP to capture the first images and set a tone. Going to a location and shooting a scene that might not even take place at this time or place is a challenge. It's just that increasingly more of the images comes from other sources than just in the camera.
I am not sure if adding a extra category will help but I would love to be proven wrong.