I don’t follow the Windows reference since my understanding was that Kerberos (the authentication protocol and associated project and software) is not platform specific, and also works on UNIX and macOS and other systems where it’s implemented for that matter. Did you think Kerberos was only on Windows?
It's not platform specific, but everything on Windows uses it, while on other platforms it's a decision people have to make (and often decide for something else, because they don't understand kerberos and it's not trivial to setup). Thus, if you haven't heard of it, you are not on Windows.
Where I’ve used it, it was not a decision I had to make (OS X, UNIX). It was a decision made by the IT departments at my organizations. So I’ve most certainly heard of it. No Windows anywhere in the picture. But I get what you are saying, you’re talking about people who have not heard of it.
But yeah, goes to show that Windows is not absolutely omnipresent.