The answer is more linguistic than political. You see, Afaan Oromoo happens to have a total of 10 vowel sounds and being able to distinguish between these is essential for any written AO text. Afaan Oromoo is also a highly stressed language; which syllable is stressed in a word matters way more than it does in many Ethiopian and European languages. Geez can only represent a maximum of 6 of these vowel sounds and none of the stresses. So, Afaan Oromoo would have had to invent a whole new version of Geez to represent words properly making both digitization and typewriting impossible.
That little experiment of using Geez to write Afaan Oromoo during the Derg is nearly incomprehensible and it butchered the language, forcing it to lose all subtlety. The latin alphabet allows Afaan Oromoo not to compromise on any of these linguistic characteristics, which is why it is also used by Somali, Sidama and many other Ethiopian languages.
Qubee wasn't adopted by the EPRDF, in fact the OLF had long been using it to produce AO text before the then OPDO declared it the official Afaan Oromoo orthography in the early 1990s. Hope this answers your questions.
But to those of you still complaining, I'll tell you that Oromos will damn well use any script they like and you don't get a fucking opinion.
Oct 07, 2020