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!
I'm aware of art history and probably never will ever concern myself too much with it accept as it may pertain to photography as art.
I see what your saying and no real disagreement as I have no doubt that you are correct, that was simply my opinion. I came to it mainly from the fact that I have some friends that are just wonderful artists and they are the least technical minded (as far as I can tell) regarding their own art. They can take anything from their mind's eye and beautifully represent it straight from their fingertips, with pencil, charcoal, pastels, oils, etc.... My point of view, though undoubtedly narrow by any measure, remains the same. It is how I, very plainly I guess, differentiate what they do regarding art versus what I do regarding art and I'm not implying any superiority of one over the other. JMO.
Chuck