Earlier you could just stick with the version you had on your CD or floppy and not care what the C-suits was up to on the company that made the software you used. So I guess it wasn't as obvious back then?
That and software wasn't a service, so you weren't chained to the price points and plan levels that executives decided. If Salesforce decides to force everybody using Slack to get Salesforce instead (which seems not unlikely), there's no recourse. We can't just say "well, we have a perpetual license, so we'll do what we want."
I still know quite a few people who still use their old version of WordPerfect. At some point it became feature complete for them and they've stuck with it ever since.
...now?