Good point. I used to work at a mobile startup that subsequently got acquired and burned - the run rate for a company of ~140 people was astronomical.
Radio engineers are expensive and rare, scopes and even faraday cages are expensive, specialist software is expensive, handsets were a fortune when you had to buy hundreds of them.
We got sold for (I think) about $330 million, then you look at social media startups that go for a couple of billion. Nobody wants to do stuff that changes the world for a reason.
I would hope that this type of hardware can be offset by the fact that these devices don't suffer obsolescence the same way other digital devices do, which need to be replaced because there's no longer 802.11b networks around etc.
In many ways they're worse, especially specialized test equipment and protocol analyzers, because they're designed to evaluate the very thing that goes obsolete.
You just don't see the volume that makes economies of scale kick in over your NRE(non-recurring engineering) costs.