Yes, those few who want or need them really want or need them. But the overall numbers just are not there.
Scanner Master even made a deal to have a lot (technical term, not the general meaning) made just for them, and they sold well for a short period of time, then fizzled out.
I don't know the numbers myself, but I trust the person who did (UPMan), and I'm sure he got those from the bean counters asking why Uniden is making this product. Uniden even made a concept app that could be used as a remote head of sorts. Nobody ever took that and ran.