Is there a history of that here? Were there earlier clear statements of expectations (like CONTRIBUTING.md) that expressed the same expectations, but in a straightforward way, that people just willfully disregarded?
I don't mean to "ding" anybody, I mostly just felt bad that things had gotten to the point where the author was so frustrated. I completely agree that project owners have the right to set whatever terms they want, and should not suffer grief for standing by those terms.