There are actually real acoustic reasons why classical and jazz music require better sound reproduction equipment than "popular" music.
>>>DISCLAIMER!!!<<<
The following opinion is a generalization, there are many notable exceptions on both sides of the fence.
Generally, classical and much jazz music have much more dynamic range, as a critical component of the music, than most "popular" music such as rock. Classical, jazz and much instumental music is often recorded in such a way as to try and recreate the original live listening experience. Imaging, transparency, and dynamic range are critical to achieving that effect.
>Most< "popular" music is mastered by compositing individual instrument and or vocal tracks. Often, the master recording will be reviewed for how it will sound on a "home" stereo system. Since "popular" music is, by defintion, targeted to the masses and many times it is mastered to be compatible with "typical" stereo reproduction equipment.
Many radio stations will reduce the dynamic range, (i.e. compand the signal) of the popular music they broadcast. This allows them to transmit at a higher average power rate and improves the average S/N ratio. Classical music stations, however, rarely compress the signal because it has such objectionable effect on the music.
Consider the live classical music concert. Acoustics are very important and if the audience is not silent it is a real distraction. Now consider a typical rock concert. The band is probably consistently very loud, the audience is screaming, and the acoustics are often horrible. Most rock fans are more keyed into the visual excitement of the band and the crowd than the actual fidelity of the acoustic experience.
I listen to a lot of classical, jazz, and popular music. I like them all. As a generaliztion, however, instrumental/acoustic music requires a better sound system to sound "good" than popular electronic music.
As time has progressed, however, the "typical" stereo system has improved greatly over the last 30 years. With this trend I believe there has been an increase in the amount popular music that relies on hi-fidelity/high dynamic range reproduction. There is, on average, still a large gap between the requirements of classical versus popular but it has narrowed somewhat and will likely continue to do so in the future.