Quote Originally Posted by Diapositivo View Post
In photography school nobody is given the assignement to "patch" somebody else's photograph because it is an exercise which has no merit and no sense. No creation whatsoever.
IMO, you are looking at the issue as a photographer, not an artist. You are viewing the photo as the end result.

But they aren't always the end. Photos are regularly used as raw materials in other artistic processes.

Training in patching and manipulation is the essence of training in Photoshop, InDesign, and other programs. Before those programs were available people did the same thing with different tools.

Art schools do teach this, a lot.