But also: the majority of academic music theory at the moment does focus broadly on the Western tradition. That's changing, I think, but a quick scan of recent articles in Music Theory Online (https://www.mtosmt.org/issues/issues.php) reveals quite a broad spectrum of music, most (not all!) of it is from the Western tradition.
Well, let's expand this: how many do in the area HN has the majority of its readers (I presume US and, maybe, Europe)?
I happen to know about a couple of non-western music traditions (because of my geography).
But it's not like those are mainstream or even merely somewhat popular outside of the areas where they are a tradition. It's not like the Austrians listen to ragas, or the Chileans to balkan polyphonic choirs (some might, but then again if we look enough, some would also listen to noisecore or renaissance lute tunes).
The kind of downside is that until the late 20th century, music education (including theory) was basically a master/apprentice relationship and even today we have a lot of that tradition baked into the formal study.