And if you have unlimited days off, and your superior refuses to give you a day off and you take it anyway, the same thing happens. And in some company cultures, just asking for vacation gives you a bad rep, because you're not dedicated enough to the company.
The solution at my office has just become that nobody asks anymore. Who wants to be the first to stick out their neck?
A bit hyperbolic sure, but not that far off. If you're given zero days off you will "get sick" more often, or whatever politically/structurally acceptable way to take time off.
Which is remarkably similar to what happens at a lot of "unlimited vacation" companies anyways - you take time off only when it can be "justified" beyond reproach.
I get your point, but that's clearly hyperbole. If you're given zero days off, and you take a day off, you get fired (or at least disciplined).