I'm guessing that most dives requiring deco stops long enough that the diver really wants a radio are probably much deeper than 10m. (Unless they're at 10m for a REALLY long time.)
However, maybe the 10m-radio could be hung on an anchor line for the deco stop.
Personally, I can't imagine needing a radio to entertain myself while underwater, even with low-to-no visibility. But then again, I haven't been able to afford the equipment and training costs for deco diving yet, so I don't know what it's like. And I guess I can understand wanting it for hours of decompression, even though I don't think I'd want it myself.