For that matter, there are still folks out there coding, professionally, in FORTRAN.

Thing is, back then, we didn't know any better. Software was a commodity, and both the people who wrote it and the people who bought it had grown up in a time before the internet, before SaaS; people whose parents who, if they made things, made widgets.

Back then, you could write a piece of software, and it was done. Then you sold it, and moved on. If the old software had bugs, if they weren't catastrophic enough to cause a lawsuit, buyers learned to live with them. It was too bad; you already shipped the tapes. And few companies employed their own software developers unless they were software development companies. Man pages have a BUGS section, and that's because there's no intention to ever fix those bugs, because that software is done.

Software today is never finished. Our first reaction if we see a project with no recent releases is that it's abandoned, or dead, and certainly that it's worse than a project with recent commits to the repo. Github is a huge culprit in reinforcing this mentality, but mobile app platforms (stores and OSes) are terrible about this, too. Google constantly changes the Play store in ways that force developers to tweak their apps lest they become incompatible, booted, or get flagged as being "old" a.k.a. "inferior."

Yet, still, there's so much software out there that's complete. An institution may hire a developer to come in and make a change, but it's usually a contract one-off; it's more like taking your car in to have the starter replaced. Those systems are going to continue keeping "dead" programming languages (commercially) alive for years to come.