Well put
William C.H.!
As the romances, Arthurian legends, the great mythical stories stem from the Middle-Ages, they naturally bear with them the medieval zeitgeist of feeling inferior to older times eg. the antiquity. (Well who forced them to deny and oppress science from the third century onwards? So it was their own fault in a way...
)
And the story of the fall in the Bible just enhanced the notion...
Although I must say
Eonwė is up to important things as well with his talk about the craftmanship versus the machanical production of goods. Uniqueness and a known history of a thing make a difference - well, today they do.
But that has been different as well and quite lately so... I'm not old enough to remember the following myself but I have heard and read about the fifties and sixties when something made from plastic & from the assembly line was hip and cool and only the poor had hand-made old drawers, baskets, clothes etc. But there were remnants of that ideology even in my youth in the seventies when a pair of woollen socks made by a grandmother were the un-coolest Christmas-present there was to be imagined. Today they would be priceless!
Is it yet agan a question of rarity then? Things that are rare are valued and those that are common are not? Like being fat was stupendously great at times and now is not (depending how easy it is to be wealthy enough to eat or drink a lot)? Like being pale-white was adored at times and being tanned is at other times (depending on whether spending your days indoors are looked at as high-class or labour-like)? Like wearing hand-made woollen socks or having a two-hundred year old carpentered table in your living room is cool or not (depending on whether the majority of the people have them or not). Etc...
It's easy to see the logic of the Middle-Ages - and that of Tolkien - work this way...