This is actually a very revealing thread; maybe it would benefit from better cables. The OP may be trolling, or may be just bewildered by audiophile fetishism; hard to tell. But the vitriol his post inspired is revealing. Those who calmly respond that it all depends on what you hear perhaps neglect to notice that we all advocate for our preferences here. If it were just up to each pair of ears to have their own preference, there’d be no need for, or interest in, this site! Thing is, we all believe that our ears, and our perceptions, are "right," so we try to convince others of this. But that’s really hard to do when it comes to crazy expensive cables and tweaks, since rarely do these have any objective criteria (i.e., science) on their side. The anger of some here with the OP suggest a great deal of defensiveness; if you really do hear a difference that’s worth big bucks to you, what difference could it possibly make to you that some stranger doesn’t? That would matter only if you don’t really believe yourself; that you have doubts about whether or not you’re deceiving yourself, and wasting your money.
Anyway, the response that "it’s all about the music" is also disingenuous. Come on, let’s be honest; it’s also about the gear, which is mostly what we discuss on this forum. And that’s fine; lots of technology is "beautiful" in its own right, and that beauty almost necessarily involves a mating of aesthetics and functionality—otherwise, it would be art, and not technology. We love gadgets; get over it, and don’t be ashamed to admit it.
The sports car analogy is dubious, too, IMO. Very few owners of high-performance cars know how to drive them to anywhere near their limits. The relevant comparison here is not between an experienced sedan driver and a sports car owner, it’s between a commuter and a competitor. How many of us sports car enthusiasts are competitors, or even aspire to be?
One more thing. I agree with the OP’s intuition that an audio system ought to reproduce the timbre of acoustic instruments as accurately as possible, and that a musician who is intimately familiar with the way real acoustic instruments sound is therefore in a good position to judge about that. Of course, most music is processed and amplified in various ways; indeed, very many "acoustic" events are as well, whether you know it or not. But that’s not the point. If "music" is what an audio system is supposed to reproduce, and not just "sound," then one needs to find a standard somewhere. Since you don’t know what an amplified rock band sounded like in the studio, or in concert, using unamplified acoustic instruments as that standard makes perfect sense as far as I can see. I suppose other familiar sounds—streams or waterfalls, trains, the human voice—can also serve that purpose. But I disagree with the OP’s claim that the individuation of instruments live is superior to what "two speakers" can rather magically accomplish in a good system set up properly in an acoustically sensitive room. My system can isolate individual performers in a smallish ensemble (say, the Orpheus Chamber Orchestra) with more locational specificity than I’ve ever experienced live. I can actually follow particular instrumental lines in a complex piece (say, a Haydn symphony) by "watching" the performer with my eyes closed than I’ve ever been able to do in a live performance. That acoustic hologram, or hallucination, is one of the principle thrills—and genuinely musical benefits—of high end audio.