The grocer's apostrophe (which I will argue should be called the grocers'(1) apostrophe, since there are many offending grocers) is the bane of my existence
(1) My phone absolutely tried to correct that back to "grocer's"
(1) My phone absolutely tried to correct that back to "grocer's"
I think you're missing the joke of the name!
So "the grocer's apostrophe" makes sense as a phrase referring to a typical individual grocer with a typical atypical apostrophe, standing in as a representative for all grocers and all their darned grocers' apostrophes.