"Storytelling" in the introduction: Math papers
I propose the following guideline as a basis for answering your question: what is "appropriate" is for the author(s) of the article to try to write the best paper they can write, and for the journal editor and reviewer to make helpful suggestions about small changes the authors can make to improve the paper even more. In my humble opinion, the editor should generally not require changes to the paper unless they feel that they are seriously necessary to keep the quality of the paper at the standards of the journal. Thus, there should be a bit of room for authors to impose their creative vision on the work, which also includes the freedom to make wrong judgment calls that annoy some readers.

If you accept the premise above, it follows that if the authors of the paper thought the story with the wine bottles makes the paper better, the editor should let them include it, even if he/she personally disagrees with the decision. 

TL;DR: within reasonable limits (and half a page sounds reasonable to me), it is the authors who should decide what is appropriate. Some readers may be displeased, but that is true about almost anything that one writes.