And it has nothing to do with this album being better or worse than any other.
I hear you say you understand and are able to appreciate the impact. I take issue with the previous quote that you wrote:
Actually it does have a lot to do with it being better than most (not all) music albums released at the time and since. If you think that, you are exhibiting an unawareness of popular music and the process/processes/techniques the principle people followed.
For example, at the time of it's release back in June 1967, there were double or triple the amount of recording hours (125 hours, I think) that were ever put into a recording of a popular musical album. Arguably, at the very least, this is an indicator of the amount of care and attention to detail. This music album had the impact that it had because it was decidedly higher in quality and uniqueness and to a broad range of public tastes.