That's not the subject. But do you really think they didn't even consider wireless?
Turns out it is really hard. You need a low latency, reliable ~10Gbps link. You also need the battery to be power all the that stuff. Putting everything inside the headset would be ideal but you also have to consider that weight affects comfort and immersion significantly.
The first semi successful attempt is TPCast but it is far from perfect. I don't know much about the Vive wireless but it seems to work better but still have its own set of issues. Both are also rather expensive (~$300).
So for now, we seem to be stuck with fully integrated low end or wired high end. I think we still need to wait a bit more for wireless high end.
