The Renaissance humanists found beauty in ruins. They took what they could dig up. They thought the best was behind them, and they sought to live up to the ancient ideals. Was this the first example of stylistic revivalism?
Later on, archaeologists got to work on those beautiful ruins. Enlightenment artists like Piranesi took a methodical interest in the remnants of Classical Civilization, and produced views of it that were part postcard, part scientific document, and part aesthetic reverie.
Finally, the Romantics found ruins beautiful, but only certain kinds of ruins.
Today, the aesthetic back and forth between beauty and ugliness, the sordid and the sublime, the natural and the artificial continues, as always.
Now, there are a bunch of photographers who love to take pictures of industrial decay. Some call it industrial decay porn. Having spent lots of time in Detroit, I can understand the frustration of the person in this link. Others are clearly entranced by the aesthetic possibilities of magnificent abandoned sites, as in these pictures on Flickr. Not sure how they would feel about their subjects if they were simply unemployed with no propsects, after working on the factory line…
This color image is almost over the top, but it looks very much like factories I visited on Doremus Avenue, NJ, which is shown in the B&W image at the top. Doremus was the center of the chemical industry in the USA during the late 19th and early 20th century. (More images here.)
Is it the romance of industry that draws them? The Ozymandias outlook? Fascination with decadence? Purely aesthetic possibilities of texture, space, tone? The image at the bottom left looks positively Piranesian, while the one on the right is simply depressing in its presentation of utter decreptitude. Would these subjects be interesting to anyone but engineers if they were functioning and in good repair? (I know there are photographers of contemporary industry too…)
Plowden was making a statement, a plea, with his photographs of American wastelands, but these images seem contemplative and a bit voyeuristic. At least on the Web, I find very little interest in what the subjects actually are, what they were for, only how they look.
Coming full circle, sort of, we have the image below which shows not ruins, but a functioning geothermal plant in Iceland. No ice to be seen; bathers and boaters frolic in this Edenic scene from Dante’s Inferno. An absolutely mind-bending union of thematic opposites.
Journey to Perplexity 
The Renaissance humanists found beauty in ruins
They found beauty and much more than that (as you seem to suggest too.)
Andrea Palladio used to come to Rome and make accurate drawings of the ruins – also since the Romans were better engineers. Then he got back to his Veneto and built villas and churches according to the engineering solutions he had so discovered.
But of course Palladio was an architect and an aesthete as well, art and science were mixed in him (no ‘two cultures’ problem during the Renaissance).
Which brings me to industrial archaeology, that here is just what the name says, a branch of archaeology. But, undoubtedly, aesthetics is mixed with it and so it is seen by the passion of those who love to establish connections between art and science.
Seeing decadence or not, living beauty, or ugliness, as decadence, belongs to our subjective impressions. Could it be – let me have a stab at it – that you Americans are living a very particular moment of your history? I perceived it also in many of your catastrophic, end-of-the-world movies (2012, Knowing etc.)
In our case, Italy, it may be that decadence is so far back in time and a given, that we do not notice it much any longer.
Interesting… Interesting also in that my investigation of this topic the other night was spurred by my memory of photographs I had seen about ten years ago of abandoned industrial sites in…Mestre, Italy!
Just a few photographers who are a little late to post modernism decay.
I’ve been photographing the lot of a vacated big box store for a couple years now. If they ever build anything I’ll photograph that but I am keeping a running history.
I’ve got reels of before and after film of my neighborhood as the franchises moved in and local character moved out.