There's a certain phrase that people from my county use to express surprise and approval. It isn't widely known. When I use it around neighbors, they know what I'm conveying, and it identifies us as kindred.
I could tell you what it is, and you might like it. You might even start using it just because you like the sound of it. And it might become very popular, and soon, all kinds of people from all kinds of places might bond over its use. Hell, people might even make T-shirts.
But I choose not to. It's a shibboleth for me and the folks back home, and that use is valuable to us. You don't have the right to force me to share it.
If I wanted to explore its etymology, survey exactly how widely it's used, or argue that it's related to a similar phrase in a nearby region, I could certainly do those things and might choose to. But if I don't, human culture as a whole doesn't get a crack at it just because I passed on the opportunity.
It's a bit of a contrived example, because I'm not talking about the Bhagavad Gita here, but I hope you see what I'm getting at. The transmission of culture between peoples should be based on a mutual interest in sharing and learning, not some sense of global entitlement.