I think you hit the nail on the head. Actually, maybe that explains why you can seemingly only rarely find meals that all the (young) kids in a family like- kids develop a taste for the things they eat frequently, so ostensibly the same household should have a bunch of overlap, but at least in my circles, juvenile siblings have very different preferences.

Though to be fair, the surviving members of my childhood household have basically zero dietary overlap now as adults, mostly not by choice (there are four of us: one's vegan and can’t digest much fat, one’s got a heart condition, one’s got fiber-sensitive IBS, and one’s got celiac’s. The first two or the last two can share a meal easily, but all four of us could only really eat baked tofu, carrots, and zucchini, which doesn’t excite any of us). Maybe it’s just more evident in kids because A) people are generally watching to make sure they get all the food groups, and B) it’s more common that parents want to only make one common meal for daily family dinners, whereas adults are more likely to do potluck style dinners with multiple options on weekends with sufficient preparation time. The four opposing diets aren’t a problem for my family, we just make sure to really clean our workspace before cooking anything for the one with celiac’s, tend to eat fruit (possibly cooked) and chocolate for dessert, and make people take leftovers home.