I had occasion to link to this in Discord this morning:
And when I was rereading it, it occurred to me that while the article frames these recipes' transition from commercial origins to family heirlooms as “plagiarism”, I see it more as preservation.
The fudge recipe that's on the side of this marshmallow fluff container isn't guaranteed to be on the next one. So unless you want to fish the old container out of the trash (and forever fight to keep it from being thrown out again) or lose the recipe forever, you write that shit down.
One of the stories involves a recipe “given away in the Macy’s kitchenware department during one holiday season back in the ‘70s to help sell Crock-Pots”—would that recipe still exist anywhere at all today if that family member hadn't preserved it?