When I was in high school, I went without lunch for a month in order to pay for my first stereo system.
When I was in college and graduate school (late '60s and early '70s), my friends and I would brag to each other about the stereo systems we had just purchased.
Friends would come over to hear our latest amps, preamps, speakers, record players, and even cartridges and needles.
"Listen to that bass!"
"Pretty clear sound, huh?"
Our love of stereo was a result of two factors:
First, nearly all of us had listened to live music. And we wanted to approximate that experience at home.
Second, you had to own a stereo system -- meaning at the very least, a record player, speakers and a receiver (a unit that combined a radio tuner, amplifier, and preamplifier) -- in order to hear recorded music.
Neither of these factors exists today.
With regard to live music, it is likely that most Americans under the age of 35 have never or nearly never heard instruments that were not electrified; they have probably never heard instruments other than acoustic and electrical guitars, drums and electronic keyboard. They therefore do not know what most musical instruments really sound like. So why would they care about getting a sound system that sounds "real?"
Moreover, the music on which this last generation was raised does not consist of much melody. Its appeal lies in beat, loudness and lyrics. And since the music is often electronically synthesized, it hardly demands sophisticated playback equipment. Those who were weaned on The Beatles, on the other hand, wanted equipment that enabled one to hear all the inner musical lines and, of course, the voices of The Beatles themselves.
Regarding the second factor: With the advent of digital music, the iPod and smartphones, few young people even know of the existence of stereo systems. An iPod or iPhone and ten-dollar ear buds is their musical reproduction universe.
Moreover, MP3 files compress music. The typical MP3 file is a recording of 128 to 192 kilobytes per second (kbps). The typical compact disc is recorded at 1411 kbps. One gets many times more "information" from a compact disc than from an MP3. When you also consider the awful earphones through which young people listen to their music, the difference is so great that even those who have never heard a quality recording can tell the difference when first hearing music on a good system. They are amazed. That's why it often takes just one hearing to convert many people into "audiophiles." But few have that experience.