I’m confused. Please explain.

I own a very nice hand-built "boutique" acoustic guitar. It sounds wonderful -- the best by far of the many acoustic and electric guitars I’ve owned in 50 years of playing.

So, it goes without saying that, when I’m listening music, I’m stringently analyzing how well my system presents the sound of acoustic guitars compared to my Boucher.

No.

I don’t expect that of my system and it’s not a problem. I guess I’m firmly in the "good enough" camp.

I suppose, had my exposure to music been on a high-end system from the very beginning, I might believe emotional engagement was a function of sonics but that wasn’t the case. I started with transistor radio and graduated to a $99 component system in high school, by which time music had become a hugely important focus for me (this was before I’d started playing).

I’ve played a classical guitar for a long time, and listened to many.  I know what they sound like, and in different rooms and venues.  As far as I’m concerned, a system that can’t get a guitar to sound real must be all wrong.

If you are familiar with piano, recordings of piano are also great tests, and hard to get right. 

I miss tone controls.  Difficult to play rock as it should be (loud!) in a domestic setting.

I more or less agree with @stuartk, so I should add that no system can fully reproduce the rich tone of fine instruments. But I think sounding “real” is the most basic requirement for a high end system, because I know what real sounds like, and euphonic, or pleasant to listen to, and not irritating, is a close second.
Purely studio productions, you can never know.

People listen to different music, in different rooms, and have their own notions of what a great system sounds like. So there can’t be any hard or fast rules. You try to get a system you think sounds good to you. Not objectively,  or to everyone. 

But I think sounding “real” is the most basic requirement for a high end system, because I know what real sounds like, and euphonic, or pleasant to listen to, and not irritating, is a close second.

You make an important distinction. The point I was trying to make was that I don’t require the level of "reality" that qualifies as "high end" in order to thoroughly enjoy listening. I’ve listened to friends’ high end systems and enjoyed the more refined sonics but in terms of my emotional engagement with the music, I haven’t found their systems to be superior to mine.

Having only recently, after a long struggle, succeeded in removing lingering "irritation" from my system, I wholeheartedly concur that lack of irritation is a basic requirement. Irritating sound = irritated listener and none of us want to be that guy!