The Chinese concept of “leftover women”, i.e. unmarried women past the age of 27, is quite well-known in the West. The idea is simply that a woman should get married while she is still young and at least moderately fertile. An unmarried older woman, however, risks remaining single all her life because men may simply pick a younger woman instead.
Not to be outdone by the Chinese, the Japanese also have a term for leftover women. They refer to such women as “Christmas cake”. Holding their women to a higher standard than the Chinese, they use this term for women aged 25 or above who are still unmarried. The reference is to Christmas cake, for which there is no demand after 24 December. This may seem a bit harsh to Westerners, but it is a pretty realistic view on women and their sexual market value, which declines rather significantly throughout their 20s.
I think there is great value in a society keeping concepts like “leftover women” or “Christmas cakes” alive. While the Western perception seem to be that they are used to disparage older, single women, it is a lot more plausible that their actual purpose is to provide some practical advice to younger women, thus sparing them the fate of ending up as an old, unmarried women. After all, what is the point in making derogatory remarks about women who have already messed up their life? There is little value in that.
Even in the West, we used to tell young girls stories about old spinsters, for instance bringing up the example of some old, unmarried shrew nobody wanted to be around, let alone marry. Similar to Aesop’s fables, such stories had the purpose of making the listener reflect on their behavior. The point was to make them think about the consequences of their behavior. Surely, it is more effective to tell a bratty fourteen-year-old that if she continues like that she will end up like aunt Betty who visits every few months and whom she vehemently dislikes, than it is to encourage her with fairy tales about strong, independent women who do not need a man. We can readily observe how this has been working out for society. Probably society would be a lot better off if we had better relationships with our extended families. Even one’s unpleasant aunt would have a valuable role to play. There is no shortage of such women nowadays anyway, and if today’s teenage women met more of them, they would probably try to not become like them.