My inexpert observation is that; there are more than one or two philosophys at work here and not all directly derived from the 'samuria' way of life.
The 'Art Sword' concept has been arond a long time sure; but was made most prominant when Gen MacArthur was in charge of Japan and was convinced to class Nihonto as art works not weapons. This was vital for the survival of these historical and culturally important artifacts. This veiw is much stronger today I suspect than it was during the time of the samuria.
Next is the concept that an object that has a functional value should be without functional flaw to retain that value. This is quite utilitarian but valid to collectors in many other fields of collection, eg; tractors, handplanes, marine navigation instruments...etc.
Then we should also factor in the Japanese paradigm of perfection in functionality and form, it is present in our Western culture but not as deep seated or dare I say it institutionalised as in Japan.
The Japanese can be compared to the Germans in their obsession with perfection in creation. It overran the West's car industry like a battletank during the 70s and 80s and America has not recovered from the intense drive to create products with not simply buyer appeal but the highest functionality and durability possible.
This paradigm or philosophy can be seen quite clearly in the manufacture of their swords, their fittings and indeed almost any household artifact from the past. They are made well BECAUSE it is possible to make them well.
One of the things a beginner to 'Nihonto spotting' learns is that no matter how cheap and nasty, no matter how lowly or functional a Japanese sword is; it WILL have clean lines (almost perfect in most cases) and a form that is not easily reproduced. This makes spotting a fake so much easier. The same cannot be said for European swords, the best are good, the foot soldiers often rough and ready.
So the debate about the value WE place on these swords will continue because in some way we all will stress one measure of value over another.
My hope is that it will never lead to the loss of a sword.