>"So when did the bar start being raised in regard to craftsmanship?
>When did it start not being desirable to gouge a tube with a file and
>leave it or leave a big glop of brazing material around a lug edge?"

it was never desireable.
people and shops that would work to that standard
were never in the vanguard. perhaps price point bicycles
were left in a 'poorly finished' state. but the best-of-the-best
always was well crafted. maybe not crafted in the contemporary
sense, but crafted nonetheless.
fwiw, i think summoning up the subject of craftsmanship often
misleads people to concentrate only on the exterior. a well crafted
bicycle frame starts from the inside and works its way outward.
it's not always or just about the clean brazing, the crisp lug edges,
or the glass-like clear coats.