haha saw this on the blog this morning.. main thing is "BY HAND".. all the handiwork.. i saw 500mm f4L production on youtube.. also not as much work as this (they have alot of machinery to help most of it).
It also applies to all lenses from all makers. Even more so to those that are manufactured by machines. Those are not just simple assembling or polishing machinery, but very specialized proprietary machinery.
hahhaha actually this is just plain old marketing at work.... the actual creation of the lens element is still made by machinery, just as what other lens manufacturers do. Those that are "hand crafted" also applies to all other lens manufacturers. And mostly revolves around testing, assembling, inspection, more testing, more assembling and more inspection and finally more testing and more inspection of the finished product.