Most of the differences we hear between amps is their distortion signature, to which most audiophiles refer to as the ’sonic signature’. I’ve described how the distortion affects the sound of the amp earlier.
Based on my newfound expertise wrt speaker cable resistance (or at least unusual speaker cable resistance), can I surmise with some accuracy that high output resistance of the average tube amplifier compared to the average solid state amplifier with typical speakers will be the dominant contributor to "sonic signature". It is able to make significant changes in system frequency response which I do not think anyone will argue with would be audible.
On the other issue, for all the paragraphs written, I do not perceive that O telling S what sounds best is the dominant issue or even much of an issue beyond some zealotry (much of that on both sides). I see that more as a deflection of the real issues of whether S can really hear the differences they claim exists and that O says do not exist. I think the average O may have some thoughts on what is "likely" to be pleasing to a wide audience based on tests by respected O's, but would accept that not everyone has average preferences.