My reaction was very different from that of "a reader from Hamilton". To me, the images were stunning, exquisite both in detail and beauty, and required neither apology nor defence. The omission of more colourful moths from other parts of the world is hardly an objection: author Joseph Scheer collected his from within a specific area (upstate New York, I believe), and there is no indication that he had any interest in doing a "moths of the world" or even a "moths of the US". That he found such a wide variety in such a limited geographical range is already impressive. He had no need for more or different specimens to prove his point.
Some moths were striking, indeed -- drab is not a word one would apply to the Actias luna, by a long shot -- but I found myself delighting even more in the simple, subtle beauty of the shades of brown (Odontosia elegans), or white (Eudeilinia herminiata), or grey (Catocala relicta), next to which even the subdued reds and yellows of, say, Hypoprepia fucosa seemed almost gaudy. What beauty might be overlooked seeing these moths with the human eye alone was brought out superbly seeing them enlarged upon these plates, often with each hair and each scale distinct.
Yes, there were areas where the image was not as sharp as it should have been had this been a scientific work, where detail is all and aesthetics, however welcome, of secondary importance. For such a work, a camera might have been the better choice; Scheer, however, was interested in exploring the artistic potential of using a high-resolution scanner and an Iris printer. Frankly, I had not even noticed the fuzziness until I went looking for it after encountering the Hamiltonian reader's review. Now that I see it, I do not find it detracts in the slightest -- it is only natural that, when the human eye focuses on one part, other parts blur away. These images simply mimic this.
As for the size of the book (30 cm. x 36 cm., rounding fractions up) vis a vis the size of your bookshelves: let me answer your question, reader from Hamilton -- you store it lying flat, by preference. If you have absolutely no choice but to shelve it upright and your shelves are too shallow, rest it on its spine, and make sure there is adequate support on either side (as, indeed, you would for any book upright on the shelf). Never shelve a book fore-edge down, the strain on the binding is much too great.