As well, a lot of the suggestions the writer makes here are both nonsensical (plenty of people recognize headphones from gaming and other home audio use ) and hardly more recognizable (a red recording light?) than what she proposes.
It would make as much sense to argue that "Most people don't read music, so using a musical note to represent something related to music won't work." Or "Many people live in apartments, so using a peak-roofed house for 'home' won't be recognized." These symbols work because they are already widely used as icons. From this, iconography (and ideographs) evolve.
I would certainly recommend, when designing new icons, to avoid obsolete or niche symbols. But this is a case where design by committee may make sense, at least insofar as the more people (in a broad sampling) who recognize a symbol, the better an icon it makes, rather than depending on what's meaningful to an individual designer in their individual life.
Reshared post from +George Wiman
A very good example of a design article that appears to have been written without doing much research. The author says no one uses "headphones" anymore, or would recognize a telephone receiver. And she suggests using a USB stick as the icon for "saving" a file, which (in the age of cloud storage and portable devices that don't have USB ports) makes about as much sense as a floppy disk. She recommends a file folder icon that has an Apple logo on it, and an outdated iPod instead of a cassette tape.
OK, fine, but these skeuomorphisms are in such wide use as icons (long after they are no longer used as actual devices) that I think they're pretty much universal even if a high school student couldn't tell you what they are. Mess with common functional iconography at your peril.
10 Outdated Symbols to Exclude From Your Designs – DesignFestival
Times are changing…fast. So fast, in fact, that often web and graphic designers forget that certain symbols or icons that they place in designs may no longer be recognizable nor relevant. Symbols that one generation recognize immediately may be completely unknown to younger users.

And iPod for "Music"? Oh do ** off.
I beg your pardon? Nobody paints any more? On what planet? Poorly thought out article.
Yeah, @Ellie, there’s a lot of “Nobody I know does X any more, so clearly nobody [who matters] does X any more” thinking there.