So, Basically what your saying is that unless one attends classical music concerts and largely listens to classical music they dont know what sounds good or accurate and their opinion is not important.
You added the last five words.
However the fact remains, that all good speaker designers I have known have done crucial final voicing by ear.
To do that you have to have frame of reference. I can not voice with music whose genesis is reproduced to a large extent electronically.
If you look at one of the largest influences in the development of loudspeakers, it was their use as recording monitors in the recording music in concert halls, churches and the opera house.
There probably was no greater influence than what came out of the collaboration between the BBC engineering department and a number of designers, especially Jim Rogers, Peter Walker and Raymond Cooke.
Now the BBC did, and still do record a huge number of live musical events day after day. There have set benchmark standards in natural balances resulting in accurate tonality and perspective. They record large symphonic works, and during the Proms multiple concerts every day for two months associated with what is by far and away the worlds largest music festival. They also maintain their own orchestras though out the regions of the British isles, recording at various venues and their own studios. In addition to regular concerts in London and the regions, they record a large number of major Festivals through out the isles, such as Aldeborough, Cheltenham, and the three choirs festival. Recordings are made in the cathedrals if the British Isles at least weekly. Their archives are truly vast.
With that sort of program, one of heir essential needs was for accurate loudspeakers for monitoring. The development of superior speakers became one of the big areas of research in the BBC engineering department during the sixties, seventies and eighties. This was curtailed after Margaret Thatcher cut their budget following huge cost over runs, developing the worlds first digital mixing desk with mixer manufacturer, Rupert Neve.
This speaker program at the BBC was seminal in the development of many British speaker companies, such as Mordant Short, Harbeth, Castle acoustics and quite a few others. There was significant cross fertilization with Rogers, Quad and KEF whose managing directors were heavily involved in these endeavors. Peter Walker was a flute player also and regularly seen in the flute section during the Three Choirs Festival.
Now the point of this, is that accurate speakers are essential tools for making accurate recordings of non amplified music. I found that to be absolutely true in the 20 years or so I was making regular live recordings largely for Public Radio broadcast. I can tell you that hearing the live event at rehearsal and going to and fro the monitoring control location soon lets you know if you have an accurate speaker.
So yes, I believe you do need a strong aural reference from live events to not only voice a speaker properly, but to choose one, at least if it is accuracy you are after. I fail to see how that reference can be music that does not have a life independent of speakers and electronics. I'm not alone in that belief at all.
I honestly can not tell if a speaker is any good or not, reproducing music that has no life outside electronic reproduction. So if live acoustic music in a variety of venues is the sheet anchor of your internal frame of reference, then yes, regular attendance at concerts free from electronic reproducing devices and microphones is essential.
Peter Walker had this slogan for Quad from inception: "The closest approach to the original sound." He would have told you you have to have an original sound.