I understand what you are saying. But, I disagree. Art is value neutral. The pageantry of the Nazis represents horrible values, but it was "visually stunning." You can disagree with "Triumph of the Will" but it is a hypnotic film, that communicates an ideal (however reprehensible) and evokes strong feelings in the viewer. In fact, it holds one enthralled and knowing that it glorifies murderers does not diminish it's impact.
I read somewhere that the Holocaust was, in its way, a work of art. It's a view worth considering. Perhaps it was the ultimate expression of man's capacity for evil. How else to explain the fascination it holds, unless it was expressing something important about all human beings.
The WTC attacks fall into this category. They were visually stunning, people were glued to their TV sets, even when the incident was replayed over and over again. Compare the WTC attacks to the Pentagon attacks and note the difference. One was hypnotic and the other was not.
Whoever denies that part the human soul that is enthralled by evil and destruction - when presented in a "visually stunning" way, foregoes any chance of understanding it.
Art is an expression of the human condition. Not an expression of moral values.
I'm not going to try to define art; too many people have already tried it and failed. I do believe that art is an embellishment, an expressive vanity of sorts, that is done knowingly and through force of will. What I'm saying is that the artist has to deliberately set out to create art before his work can even begin to be considered art. I mean that in this sense:
You may drive by a mangled car on the side of the road and think you're seeing a work of art because you find it "visually stunning", but if the driver wrecked his car, because he slammed on his brakes to avoid hitting a deer, not because he wanted to provide you with an exhibit of his artistic genius, then you are not viewing art. And, if you think you are, then you are a sociopath, so detached from the reality of another's pain and suffering that you could see an up-close tragedy as something distant and surreal, and declare it a work of art.
You said: "Art is an expression of the human condition. Not an expression of moral values."
Using your definition, the basest pornography would fall under the heading of "art".