There is no such thing as an artist: there is only the world, lit or unlit as the light allows. ~Annie Dillard
If everyone is an artist, as I believe we all are, then it reasons some are more comfortable exposing their souls, then the term itself is irrelevant as there is no need to distinguish between human and artist, or neanderthal and artist, or animal and artist.
The being sharing their art is shining a light showing us another perspective of the world. The light may alight upon a soul showing emotional scars from unrequited love. It may illuminate an owl floating across the night sky, expose the hypocrisy of government officials in a satirical cartoon.
All art illuminates either the world around us or the world within us. The more shared, the better our ability to solve the riddle of existence. Were all to share their own shade of light, the mystery may just be solved.