OP maligns people for not knowing what it means, but it seems like it’s a nebulous term with no concrete meaning.
Saying people don’t know something is not maligning. Most people don’t know most things.
"You don't know this thing that nobody knows either" is not very informative. Though to be fair "grey-zone" is a bit like obscenity: you know it when you see it.
I don't think obscenity has any sort of consensus, it's based on arbitrary morality.