Wires are suboptimal but tracked wires (just like the headset is tracked. i.e. you'll see the wire in VR) should alleviate this problem until wireless technologies mature.
Mobile VR will provide room-scale tracking without wires in 2016. Watch this space.
Positional tracking with a smartphone's built in camera is already possible[1] thanks to SLAM[2]. Let me say that again, Google Cardboard and GearVR can (technologically) do positional tracking, right now.
The reason they don't is probably because you have to spend time scanning your room. But that's a really poor reason, I agree with OP, we should expect to see this happen very soon.
[0] https://www.reddit.com/r/oculus/comments/3axtxl/streaming_to...
[1] https://www.youtube.com/watch?v=e7bjsIqlbS0
[2] https://en.wikipedia.org/wiki/Simultaneous_localization_and_...