As a homeschooler, I have some insight. Here is my response, which should be applicable well beyond Buddhist tradition:
Eternal Truth---all that is pointed to by the Buddha-Dharma---is independent of time, place, language, and culture. It exists whether or not it is acknowledged. It is all around us and it is us. It does not have to be integrated into our lives, and it does not have to be recreated by every generation.
To a skillful teacher, every situation---time, place, culture, circumstance, and so forth---presents a gateway, an opportunity to point to the truth. That teacher moves freely everywhere knowing that the dharma knows neither holy nor unholy.
Labeling the practice of a particular time, place, culture, language, tradition, and so forth, locking it in time and clinging to it, is worshiping an idol, killing the Buddha. It is the greatest insult to the teachings you wish to preserve: Impermanence.
Yet, what allows this delusion at all?