Don't get me wrong, I really like the device but it needs a few more years to be easy to use and maybe a new hardware revision to get better performance. I get about 9 hours standby time (wifi on, modem off), at least the screen on time is pretty good.
And maybe for creating playlists? And maybe for modifying playlists? And maybe for searching for songs/albums/artists? And maybe for modifying metadata?
Considering all these features that needs to be supported it makes sense IMO that it's a specific protocol.
For isolating your database from your host OS.