Why is it that Sojiro's playing of ocarina in Great Yellow River has lead to the development of a diverse playing tradition in Japan, whereas the use of the ocarina within the zelda games and people's exposure to them has not lead to the same kind of diversity in the West?
Many people that discovered the ocarina through Zelda seem to only be interested in playing zelda tunes. Some people explore video game and anime music more widely, but still few people appear to explore the full musical potential of the instrument.
On the surface these two situations, Sojiro exposing Japanese people to ocarinas, and Ocarina of Time exposing people in the West to ocarinas, are comparable. Both exposed the instrument to a large new audiance, but how they have played out are vastly different.
Presumably there were people adopting ocarinas for playing Sojiro's music verbitim in Japan, but something happened that caused an independant playing tradition to develop around the instrument, a tradition that is self-sustaining and stands alone from its originator.
In Japan there is large-scale instrument production, people composing new music for the ocarina, and professional highly skilled players and teachers. In the west, ocarina has mainly developed along a path of visual novelty and 'easy to play' marketing.