Because there is more value in understanding someone else's ideas than as some kind of cultural favor? East Asians built empires, invented and discovered incredible things. They have developed elaborate artistic, musical and familial traditions. All of that is of course related to their cosmological ideas. If you could, why wouldn't you understand ideas that were integral to so much human activity? And if they fail to understand your culture in the same regard, that just puts you at an advantage.
In the words of my old man, "I'm not telling you what I know, cause then you'll know what I know plus what you know and then you'll know more than me!"