When you come up with an "aha!" explanation for why something is in your story, stop. Write the idea or explanation down, and then do everything you can to examine it, because sometimes you might need to rethink.
I still go to writing conferences, even if I'm not writing as much as I used to. One of the panels I attended was called "Worldbuilding: How Language Shapes Culture." Sounded very much up my alley, so I went to check it out.
Overall, the panel had a lot of good advice! At one point, though, a panelist said something that bothered me. He said, "We have a word for a child who has lost a parent, and that word is 'orphan.' But we have no word for a parent who has lost a child." This is all well and good, and at face value seems true enough. Then he went on, "I can only imagine that losing a child is so awful we, as a culture, couldn't come up with a word for it."
Unfortunately, I've read a lot of economic history, and as Brad Delong pointed out in his amazing Slouching Toward Utopia, there is a word for a parent who has lost a child, and there always has been.
That word is "parent."
Before the invention of the vaccine, bolstered by better nutrition and public hygiene, the average woman of childbearing age had to have five pregnancies just to see two children reach adulthood. The other three children died; on average, two within the first weeks of life, the other somewhere in the first seven years. Scarlet fever and respiratory distemper were rampant, and typhus and smallpox ripped through cities, killing many their wake.
We didn't need a word for a parent who had lost a child. If you were a parent, it bordered on the miraculous if you hadn't lost one or two already.
The word "orphan" exists not because it was a particularly awful state, but because it represents something more than the child who has lost both parents; an orphan is someone that needs to be dealt with by a community, someone who needs shelter and food and education, who may yet contribute to the survival of the community. It's an economically powerful word, in that it describes both a cost and a resource to a community that, for most of human history, teetered on the brink of starvation.
This is an idea, "losing a child is so horrible we don't even talk about it," that needed to be re-examined. Because it's really, "losing a child used to be so commonplace we didn't need a word for it." Maybe we do need such a word today. But when you introduce such an idea into your story, have a second thought about it, and make sure that your notion and reality don't just make sense in a story idea, but if they make a claim about us and our world, that the claim is accurate.