Some of us can play to remote speakers (AirPlay) which makes this more handy. I can choose what room(s) to play something in from iTunes. If someone comes over and has a new track they want to play for everyone it's now easier. Still not as easy as it should be, but nothing with the RIAA / Apple is perfect.
There's no technical reason to prevent people from getting music back off their devices. So the assumption is it was part of the DRM requirements that Steve Jobs claims the record labels forced him to accept.