<<I know bikes are about more things than craftsmanship but when did craftsmanship start becoming important?>>
My two cent theory:
When the US became a major market for bicycles. Americans have more disposable income to spend on toys, and they view the bicycle less as a pragmatic tool, and more as pleasing hobby, and a thing of beauty, than their Euro counterparts. American consumers were willing to pay for the prestige of boutique bikes, where Euros were less concerned with details of appearance.
Also, the competitive nature of the US economy allowed boutique builders to distinguish themselves, whereas the old-boy economy of Europe tended to support the established name builders.
Fancy-lugged, fancy-finished Brit bikes are an exception to this theory.
Side note -- I remember being very amused to hear people waxing rthapsodic over the lovely finish details of 70's Italian frames.
Peter Bridge DenCo "Ain't nuttin wrong with a pinned Colnago"