Well, I can’t get quite so indignant; all art uses some resources. For example, I could imagine going to a lute recital, but the building of that lute would have caused a tree to fall. The food and the camera are the tools of one artist’s trade, just like oils on canvas or bronze for sculpting are another’s. All take from the planet. All are “wasted” by this measure. The only difference with this particular artist’s work is that the depletion to our natural resources is made explicit. So unless we are willing to do away with all art (and all of our pleasures, really), we may as well enjoy the food art along with the lutes.

I spent my first five years on rationing, in Britain, and when we came here, my parents continued to ration; all my life there were two things that were drummed into me: 1) Think about tomorrow before you eat that, or throw something away; 2) there are starving people in India, Africa etc, who would love to be able to eat those vegetables (only one time did I talk back, and got my father's hand for the trouble)
I have come to realize that those starving people are starving, not because of the meals on my table, but because of politicians and CEOs who put greed above caring for the world. We CAN feed the world, and do it handsmomely, without making kids feel guilty for wasting food or fearing for tomorrow's meals, we only need the will.
There is nothing obscene in what this artist has done, only in the self righteous attitudes of people who claim he is wasting food. If he is saving 50 to 60% of the food, how much have YOU wasted over years.
As one other artist said, as he drew on the ground, "LET HE WHO IS WITHOUT SIN, CAST THE FIRST STONE!!"