Categories are so innate to the working of the human mind -- we do it regardless whether we talk about it consciously or not. But the moment we verbalize it, at least it becomes questionable and directable as you become aware of how you tick. Even this discussion about the sense of it uncovers what needs to be uncovered. Just that you are not better off having no discourse at all, but the right discourse at the right measure. I guess as of now we have established what this should be about and what not.
re: photo & "copy", since we are at it...
Post-modernism has not only defeated the idea of authenticity, but of originality at large. It's not anymore about whether a work is derivative, but more or less complex composition of derivative -- what transformative effort was added. Photo-sourcing is only consequential philosophically. The integration of literal photo copy into artwork is no invention of computers, it existed long before in kinds of installations/collages/mashups; Photoshop merely "perfected" this artform, not least on non-literal grounds. It's a different effort rather than less, as is a different taste. Personally I come from the modding scene of games; the approach of re-use, interpretation and modifaction of assets is a natural idea to me, and I recognize admirable skill there in its own right, it's not so much about some cheap "tricks", it's about having good ideas, it focuses on the conceptual aspect of art -- that's why few are actually good at it even though everyone thinks it looks easy enough to be good at it; like, most custom maps in Warcraft3 terribly sucked, it needed very special personalities to pull off the good stuff, and I don't mean Dota...
Frankly, it is weird I find myself "defending" techy art here, when in other places I mostly held high the classic history of arts at large and pixel art in form of age old cross-stitches and tapestry in direct ancestry. I don't think there is just this big mainstream of anti-classic art out there. Now there are countless of concurrent streams out there, non of them really threatening the other. Maybe there is this sense that some form of art is felt under-appreciated than it deserves. But in the end it's all ... you know... holistic. It's all there to learn from and have fun in. Aside from a professional job in which you serve demand.
Classic and pixel art should not feel so high-brow as to ignore trend and Zeitgeist. Rather it should search for ways to invade every other (plat)form, an active effort for relevancy, rather than taking attention for granted. That is to say, the artist must realize his existence beyond egoistical interest, and absorb society's interest as part of his own. A wholly growth experience, a grown-up existence. "I" is nothing without "we". "you" are irrelevant, and "we" are incomplete.
So the purpose of this topic might as much be the past of pixel art as its future off-spring, with their own peculiar challenges but obvious lineage in translation.