I honestly don't understand the resistance to conceding me this point. I can perhaps understand if people aren't as bothered by this kind of thing as I am,

I don't understand either. I agree with you that it is the wrong phrasing to use (when you say "I won't grade it" and expect that to be equivalent to "I will give it the grade 0"). I'm certainly not as passionate about the issue as you are, but it seems like a valid point. I've been reversing some of your downvotes on this.

Please count me as a counterexample to you-know-who's claim of "You are not obviously right to people other than yourself."