The post is excellent, but I think he’s not giving enough influence-credit to the software reflecting the hardware of the time. The pinstripe texture looks like the front of the iMac G3s, and fell out of favor/prominence when dropped from the hardware; now the subtle grey reflects the refined aluminum of the the hardware line-up. (Visual coherence, branding and marketing, but also another kind of realism: what’s on the screen looks like what’s holding the screen.)
But his point is still completely valid: the original QuickTime 4 player with its vertical “virtual thumb dial” volume was, um, not great, but the experiment in direct manipulation and realism has led to the interface that you actually directly manipulate. But that was the beginning of rethinking Apple’s approach to interface design, and was both brilliant and important, whether it worked or not in practice.
