I think most people just haven't been trained to see what quality work looks like.
I do beleive you hit the nail right on the head, you are correct if you havent seen the quality of say aloha for example then a run of the mill average paint job in my opinion, now becomes "show quality". Over restoring is a good point to bring up, if one is happy with the defects that a car had when new, then that is fine with me. This corvette for example, the owner knew that these cars were very wavy when new, and wanted it as good as it could possible be, he just could not stand looking at all those ripples and poor panel alignment. On the other hand the guy he bought this car from who has a private collection of ridiculously low milage vettes in original paint, cant see making one this good. So its up to the owners preference and each person has there own definition of "show quality".