A confident nation builds so that future people may look back and marvel at their ancestors ingenuity and aesthetic vision. A nation in decline looks to the past in a vain attempt to “preserve” what was once great. Preservation is what you do to dead butterflies.
Ironically, if today’s rules for historical preservation had been in place in the past the buildings that some now want to preserve would never have been built at all. The opportunity cost of preservation is future greatness.