Well, it's their reason reason. We won't know unless we ask every single one of them.
But then, come to think of it: Audio files are non-functional data, so there's no need for them to have all the freedoms as functional data like software have[1]. However, we must still study the case of audio step timings for use in games like Frets on Fire, StepMania, and Performous. And this case puzzles me for the following reasons: Perhaps my view of functional data is a little misaligned, but I think that, although the step timing seems to fit as something with which practical things can be made with, it alone isn't able to aid on making things based on the step timings. Instead, it seems to depend on other non-functional data. I see this situation as a ODT file, where you can save things, move things around, but it depends on document editors, text fonts, multimedia, and so on, but you can't really create a software using only that ODT file, but instead, you can create other documents.
