It's always been more than a hobby. Art is more than a piece of canvas you look at and think "that's nice". Cave paintings were more than pretty pictures they were communication, history, instruction perhaps. Life was hard, fast and short then. I doubt they purposefully made different colors of pigment and fingerpainted without a good reason. Before the invention of the photograph portraits were done on paid commission. Carvings, statues, engravings, they all have a purpose. Much art was created just for the fuck of it, much was created upon paid request, yet others were created out of religious ideas/reasons. My point being art probably started as a cross language form of communication and record of events type of thing and slowly evolved into what we have today. As new tools and techniques come into being new art will follow.