WK Audio closed?

As I pointed out, and as Brian pointed out; these things are not serviced anymore, and spare parts are no longer available.

How many/much software dependent hardware (or hardware dependent software) audio gear have been abandoned, discontinued or otherwise left behind throughout the history?
Plenty (Steinberg among the worst hardware wise).

You are correct up to a certain point only.
Software evolves. And needs to evolve in pace with the OS’s and the hardware. So you know that after a matter of time you will need to upgrade, or that the application will simply stop working. Granted, there are examples, like the DTS encoder, which were abondoned, for reasons which make perfect sense to the company that developped them (the fee asked by DTS was so enormous that it simply couldn’t be kept alive) but makes no sense to the user.
The point that while the user expects software to become outdated, he/she has the idea that the hardware will be around forever, it simply isn’t.

I own a bunch of great vintage gear, like an 8-rack of Neve 1772’s, a tube U47 and much more.
The matter of fact is that it costs me handsfull of money to keep them working, and I know fore sure that at some point, no spare parts will be available anymore, and my equipment will simply drop from a value of $5000 to a couple of nickles and dimes for spare parts.

It’s all a matter of perspective …

Fredo