MIDI cannot work its way back to the original score itself, but it can capture a perfect performance of the score and allow that performance to be notated in another scoring program. That doesn't quite get you back to the original score however.
So now I suppose I can see some value in trying to develop more score representation formats with more compatibility - it'd be cool to be able to write a proper score then drag-and-drop it like MIDI into a DAW. Yes, that's usually possible through MIDI export, but it'd be neat if that was a first-class feature and we all passed around scores on the web instead of MIDI files.
EDIT: On further thinking, passing scores around wouldn't really be sufficient either, as oftentimes you do want a copy of an exact performance with humanized timings. I suppose you really would need to embrace both formats, or create some sort of hybrid that can capture elements of either/both freely.
Music is really just a non-verbal language. If you become fluent in the language, you can appreciate music in its textual form just like you can appreciate Shakespeare for its literary value.
To my mind, this is why notational representations still persist, even in the age of media recordings. That higher level of abstraction still carries plenty of value and its compactness (over performance) is convenient to creators and academics who wish to reference them with fast read access.