Because I add files every few days. I can't change permissions every time I do so.
And we use Traktor Pro as well, and iTunes (in case MusicBee starts acting up), which are using the same files. Altering files is not a good idea since other programs depend on these files.
Also, they are FLAC files, 3TB of it. If the drive fails, I have to use a backup, which don't have the ReplayGain tags. I have two drives like that, perfectly tagged. I would need to swap the drive with an identical copy of what was on the failed one.
MusicBee works perfectly without altering files and using it's own library. I don't see why everything's working using the library, except this. I feel it has been left out.