Such kids-seniors relation is not a requirement of nuclear family structure at all. Somehow people managed to keep nuclear families intact with very wide range

Such kids-seniors relation is not a requirement of nuclear family structure at all. Somehow people managed to keep nuclear families intact with very wide range of intra-generational attitudes. A lot of critique of nuclear family is talking specifically about family where kids are raised by parents and how that is unfair to kids who weren't so lucky with good parents. In the early soviet union, some of more radical revolutionaries wanted to just put all kids into foster homes to ensure a fair start for everybody. And prevent non-state-mandated ideas from finding a way from parents to kids. Intra-generational legacy is a touchy topic as well.