I don't want to beat a dead horse but I'm bugged.

You posit they'll all sound the same,  apparently, you trust the measurements over human sensory perception.

We need to be clear about something. You specified that the measurements would be the same, and I have to assume that includes all measurements, not just 'some'. If that is true then indeed they will sound the same, having the same bandwidth, same distortion spectra, same distortion vs frequency curve, same output impedance and so on... yes, they will sound the same.

My point is that the important measurements just simply are not made nor presented. 

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.

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.

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". 

Amp and speaker interaction cannot be simulated in lab amplifier measurements. Most all loudspeakers vary dramatically in load to an amp. Testing the amp and speaker separately is not an accurate measurement of how the components work together. Some speculation can be made sometimes but not always. So the method used is measuring with a simulated 4 ohm load and a simulated 8 ohm load but that is not how the system is operating.  

Amp and speaker interaction cannot be simulated in lab amplifier measurements. Most all loudspeakers vary dramatically in load to an amp. Testing the amp and speaker separately is not an accurate measurement of how the components work together. Some speculation can be made sometimes but not always. So the method used is measuring with a simulated 4 ohm load and a simulated 8 ohm load but that is not how the system is operating.

My EE circuit skills at this level are not superb, but my expectation would be this is a factor of the stability of the amplifier which could be impacted by the impedance of the load compared to a pure resistance. I would expect amplifier designers such as Atmasphere consider this, and also that for most standard speakers (not electrostatic for instance), they expected range of speaker reactance is not so great they cannot account for it. When I was researching speaker impedance after discovering the high resistance cable, I noted that the phase angle seemed to be bounded though my research was not extensive.  It seems an inherent element of most speakers is some significant series resistance.

This is a good point but not the nature of my question. If the amplifier has a characteristic output resistance that is significant, then knowing the characteristic input impedance of the speaker, we can simulate/model how that will change the frequency response. This has been validated by an EE strong in circuits so I am confident that is correct. I believe that would be dominant over distortion, but I am not fully confident in that belief.   I do understand that high output resistance would also impact woofer movement which may not be easily modelled.

we can simulate/model how that will change the frequency response. 

I seem to have an attraction to hard to drive loudspeakers. Some with wild impedance swings and nasty phase shifts. I had one amp that totally rejected one frequency with one loudspeaker and a switch to another amp proved there was not a speaker issue (other being hard to drive). Not sure you can simulate that without using the loudspeaker.