Its not about encryption, and real world concerns are echoed there. Radio (or other broadcast) gives up lots of signal intelligence; times, location, correlatio

Its not about encryption, and real world concerns are echoed there. Radio (or other broadcast) gives up lots of signal intelligence; times, location, correlation with other events etc. A tightly collimeted/focused media (like laser) reduces those risks while having other benefits like a reciever detecting interception via attentuation.