It's a cynical comment, but one that (sadly) may serve users well.

It's like the "assume your equity is worth zero" heuristic that many of us (including myself) employ when advising friends. It's not strictly accurate, and if taken truly literally it may poison the well for the startup ecosystem, but following this heuristic would prevent painful events for many employees.

Not toxic at all. It's a very accurate comment.

Having been in numerous situations like this, I actually now "know better" than to rely on some 3rd party API that's not easily portable.

That's probably why most startups that provide infrastructure as a service are built on open source (using open standards) from day one. Otherwise good luck getting any traction

Should know better than to rely on and pay for a service without some kind of assurance that it won't simply be switched off with little warning. Maybe expect a bond big enough to keep the service running in its current form for N years?

It's better for potential users to be aware of how often this happens, than go on in ignorance of it.

Should know better than to be locked into products and services online. Buying a hairdryer from Amazon is one thing, as the hairdryer is 'immutable' but relying on a product for a workflow at work or your day to day life and having it pulled is a danger. That's why I'd use Jira or MS Word over something offered by shiny new startup. Even better use markdown files on your local drive. Back it up at Dropbox sure but make sure it is backed up somewhere else too(!).