The last time I posted in this thread I said photography is like Jazz, you just play and there are no inherent reason as to why.
I think the answer is rooted in the concept of the demiurge. Most cultures have a creation myth, and most people profess to believe in creator deity or deities. We have a need to explain why we are here.
But we do not explain, to the best of my knowledge, why the demiurge felt the need to create the universe with us in it. We often ascribe motivations to why the Creator did this or that after having made the universe, but not the original motivation.
And so we create. Much of what we create serves a function, and so it can be easily explained. Growing food, building shelter, making clothes, these are all things that are needed to sustain life, society, and the cultures we have grown accustomed to. Art, not so directly.
Many have tried to explain the creative urge, and while I am sure many have touched on valid reasons, I have never read an explanation that I felt was complete. I suspect the true reasons are buried in the psychology of why we humans do anything, and may be different for different people.
One reason which I have often felt had a ring of truth to it is the belief that we create art for the same reason we procreate - to cheat death.
Procreation is perpetuation of the species, and some might consider that an instinct, as it certainly appears to be in lower animals. But humans appear to regard procreation as something more personal than simply making sure that humanity continues - we see it very much more personally than that. It seems to have a lot less to do with instinct and a lot more to do with choice, in many cases.
We do not want to die. We will all die. We daub pigments on cave walls so that if we must die, something we made may survive us. Our one shot at immortality.
Why else do we talk about things like preservation of film, digital images, and the archival qualities of various substances?
Sometimes I wonder if the demiurge had the same motivation.