I don’t see that building non-durable furnishings is bad in any way.
The things you build to last really depend on the resources you have.
Sometimes it is more economically efficient to build cheap stuff that doesn’t last. People want to change how things look from time-to-time. Why build something that will last for 50 years if its style will be outdated in 5 or 10 ?
College kids and young people in temporary living situations don’t have money or reason to buy long-lasting furniture.
Before your parents bought that oak table, what did they have, I wonder ?
Also, keep in mind there is a significant availability bias here. It is easy to assume that stuff was built well when the only things you see that were built 50 years ago were the things that were built to last 50 years or more. I’m sure plenty of cheap crap was built from inferior wood with inferior craftsmanship 50 years ago that is no longer with us. It’s just that we don’t see it because it is gone.
A couple years ago we took the family to a pilgrim village in MA. They said when a family would move, they would burn the house down and sift through the ashes for nails. They would bring the nails with them to build the new house. So, in a way, the whole house was disposable, even in the olden days.