Although Carbon bikes that are laid up by hand and genuinely full custom are available (I know of at least one company that offers carbon custom in 1mm increments...), it's relatively recent. BITD when carbon was a new thing for the masses, only the big boys could do the R&D and production, and they were (as mentioned above) soul-less. The status of the filet brazed or lugged frame made by someone you might have met and certainly knew the name of became more and more desirable. To me that places the date somewhere in the 90s when aficionados might have tried carbon, or researched it, and largely rejected it in favour of the feel and consistency of steel.