And this is a good example of what I mean: They didn't really have the time or resources to write new music or adjust existing music to fit what they were doing with it, and either just ported over all of the songs early on in production or the various people working on it failed miserably at communicating what they were working on with each other, so when the time came for putting which songs where, it mostly ended up as "eh, we haven't used this yet, might as well stick it here."
Note: I know literally nothing about this game's development cycle, but I have seen this exact pattern of behavior enough times to recognize the results it yields.
A small, pointless translation note: