This is completely a wild guess on my end:The only design choice that kept me away from this machine is the side audio input jack. I plug my powered speakers into a receiver and having this stick out on the side is a no-go for me. Yes I know I could go with an AirPlay solution, but that just adds complexity to a design choice. If the power brick can accommodate ethernet, why not audio?
1) the combination of power and audio might cause interference on the audio bit. ( noise )
2) de brick is designed to be out of sight, you won't be accessing it regularly for plugin in/out. As such, putting the jack there would be impractical.