On a second read of your comment, I must say, I slightly misunderstood you and replied with this misunderstanding. I think if the music itself is "obsessed" with a certain structure there is nothing wrong or bad or misguided about being "obsessed" with that structure. In this case, if these modes are truly ubiquitous in Ethiopian music, nothing wrong with teaching, studying or using them. My original post was intended for people who are learning from scratch. I think it's better to understand the intervallic structure of a given music or musical repertory, instead of just the scales. But there is nothing wrong with scales themselves, as they're truly very useful models of music.