Earlier quoted context omitted.
>the software produced 20 years ago still has value Which unmaintained piece of software written 20 years ago still generates revenue?
I would imagine that there's probably a _lot_ of industrial machinery control software out in the wild that's still running on Windows 95/98/etc., where the company that wrote it probably went out of business 20 years ago.
Therefore I disagree with this conclusion. I think software is the thing which gets obsoleted and rots the fastest, not the hardware. Which is why SW development is in so high demand and wages so high in contrast to HW and mechanical engineering.