Jacub talks about most people viewing photography as reporting. I'm not sure that's true - clearly he does and many others do, but I have no idea of the percentages and am convinced it isn't the majority of serious photographers - see Chuck's comments.
Interestingly, the more dramatic the lighting, the more unique the weather, the more unusual the landscape, the more I want it to be "real" and not the result of someone's imagination and skill with Photoshop. Mind you, I don't tend to look at those kinds of image as fine art, more like the reportage that Jacub and BJ mention. One can still admire the luck and or skill or patience, perseverance and effort it took to get these kind of images, but one tends not to admire the image for itself.
John Wimberley has a wonderful image, "angel descending" which clearly isn't "real", unless you have rather unusual religious beliefs. As it happens this image was taken in a swimming pool but had he used Photoshop to create it, it would have been every bit as good. I don't imagine anyone criticizes him for not using a real angel (union rates being what they are).