And insects had previously mastered winged flight many millions of years before either group. Obviously wings, at least on this planet, are a kind of universal design path of least resistance for organisms that evolve the habit of flight. In a similar fashion the shark's torpedo shape is universally the best way to design a creature to ply the open seas when the evolutionary parameters call for immense speed, strength and agility. Unlike in nature, and unfortunately for the PC manufacturers, Apple holds copyrights, which prevents the competition from evolutionarily converging on the iMac's universal form. There is nothing cosmetic about Apple's choice of design for the iMac.
Fashion sense has little to do with absolute dominance over an ecological niche.
Just ask a shark - its basic 'cosmetics' have needed little evolutionary alteration in the last 250 million years. People respond to the iMac because they instantly, if unconsciously, recognize its form is as tightly linked to its function as a shark's shape reflects its nature. Perhaps because of a million-year history of tool making, the human mind is hard wired to find such elemental merging of form with function inherently pleasing at the gut level. That is the secret to great industrial design and, ultimately, the insight that great art brings to our lives. It's why humans have always painted pictures, built cathedrals, composed songs and desired the next insanely great thing.