Jim,
A lot to think about in your post. Here are some of my thoughts.
I know for a fact that many older guitars of a certain brand and model sound better to me than newer guitars of that same brand and model. As an example, my 1936 Martin 00-18 sounds better than any newer Martin 00-18 I have heard or played. Is that because of time, materials used, craftsmanship, a combination of those three or something else???
I know for a fact that my hearing and vision aren't as good as they used to be. So does my guitar sound better today because I play better or because I can't hear as well? I know I look better.
If we had forty (50, 60 or 70) years, we could do a controlled test of several guitars (and/or any thing else) by recording them in a controlled environment. Then each year record them again using the exact same parameters - same strings, same room, same mics, same recording format etc etc. We could measure volume and forces required to attain a certain volume. Measure sustain, etc etc. After forty years we could listen to and examine the data for the forty different recordings to see if in fact the guitars sound/tone changed. Then we would know from a factual basis not a presumed basis.
Perhaps the most important, to me, is to carefully consider my responses to posts before submitting them. Are those responses based in fact or opinion? Are they expressed in a fashion so as to encourage acceptance as such and not judgement or commandment?
Thanks,
Brian