You could make the same argument about listening to music, that wandering around while listening to music will get you shot or eaten by wildlife, and yet people generally gain some benefit from listening to music.
If someone is selling a fundamental truth about the universe, it better damn well work in every situation
Japanese Buddhism is so different from Chinese Buddhism because the cultural background of Japan is very different to China, so people have different needs, propensities, and capabilities.
Seems like a strange thing to say. Fundamental truths don't have to be useful period, let alone be useful in every situation.
If someone tomorrow proved that life simply had to be common in the universe, that would hardly be useful to any situation you'd face in your lifetime.
They have to if the fundamental truth pertains to the One True mental state one should achieve
I probably should have used more qualifiers to make the context explicit...