Not to put too fine a point on it but...
Perhaps you aren't aware of concerning yourself with art history. You can't, however, escape it. Mankind, I believe, leaves only two things behind itself in time: art and garbage. We choose to save the one, the other often lingers even longer. Sometimes, we confuse the two.
As for the ability of the (non-photographic) artist to "take what is in his mind and put it straight onto the canvas" ... I'm afraid I disagree here as well. I admit to being a bit biased, having taught painting for over 30 years, but the craft of painting is at least as technical and demanding as that of photography. The fact that some who call themselves artists never bother to learn it is no more telling than the fact that many "photographers," even before the days of digital images, simply pointed the camera and pushed the button. Some even got lucky and got a keeper or two!