When I think of writing being called an art, it causes me to think of the why it may be called that. When a writer is transferring thoughts from the mind or imagination, to paper, or as may be the case today... to screen, it does become Art. The ability as much as it is a Need to cause the reader to "See" what is being written is in fact Art.
To write without the ability to create a canvas painting or a Big Screen scene while writing leaves the reader with only words. Words that could be tossed into a Dictionary or a letter to an unknown person. They serve only to fill in space. It is truly the writer that can create a scenario for the reader that comes to life as if it were 3-D or Live , that creates with their mind the painting that will endure and last in a readers mind. To take a simple barn and cause it to become the "Red Barn that stands alone in a field, it's paint peeling from the wood, straw left long ago to dry and be blown into the wind, sticking out from the open window at the top of the now nearly colorless barn" is the same as painting a picture for the reader that they can see as well as feel.
Such is the life and the desire of every writer. This is the essence of their soul being layed out in the open for all the world to see. If a writer can capture this very vivid picture for their readers then he has indeed made writing "an Art." I am confidant in myself that I have done this for you, the reader in both of my novels. Be prepared to not only read the words, but to feel them as if you were sitting right where the characters are.