Dear me, Isaac! The question, "Aren't there a few points you guys seem to be ignoring?" was merely a general expression in common language of my impression, after skipping through the responses in this thread, that essential questions about this photograph that occurred to me
, were not being addressed.
However, if you wish to get philosophical, the answer to your question would be... 'most guys on most subjects throughout the ages, and during the present time'.
To get back to the topic, Eric made a reference to the print's humongus size, without mentioning how large, and Kencameron mentioned he'd reserve his judgement until he'd seen it full-size.
If one accepts the recommended viewing distance from a print as being 1.5x its diagonal, then Gursky's 12ft wide Rhine II should be ideally viewed from a distance of 20ft or more. The sheer size alone makes the print more suitable for wealthy people who can afford to live in mult-million dollar mansions containing at least one huge room.
Other issues that occurred to me, simply because of my general interest in photography, are the resolution of this huge print and the type of camera used. If the scene was shot with a single frame from Medium Format film, then the print might appear rather fuzzy from distances closer than 20ft, depending on the type of sharpening applied.
Don't many people, particularly photographers, like to examine large prints from close up? I haven't been able to find any 100% crops of this Gursky print.
The general outrage and amazement that such a high price could be paid for something which is essentially a photograph, despite its huge size and the artistic manipulation involved in the processing, is perhaps overblown.
Things that are either scarce or unique have a history of attracting ridiculously high prices, such as rare postage stamps, a pot of gold, or lumps of highly compressed carbon, often referred to as diamonds.
I ask myself, which is more ludicrous, paying $4.7 million for an impressively large print depicting a very peaceful and idealized scene across the Rhine River, which you would rarely find in the real world due to the ever-present dog-walkers, cyclists, pedestrians and occasional factory... or, paying $4.7 million (or more) for a lump of highly compressed and polished carbon which merely glitters, and which is usually locked up in a safe out of sight, for security reasons?
Another issue is the reproducibility of the Rhine II print. A photograph of a painting is still a photograph and the differences between the two can be easily discerned. But a photograph of a photograph can be visually indistinguishable from the original, without forensic testing.
If I were to own this print from Gursky, one of the first things I'd do is make a copy of it. I'd even be prepared to buy the best Nikon prime to use on my D800E, and take multiple shots of it for stitching, so I could capture even the texture of the photographic paper used for the original.