Earlier quoted context omitted.
This is not always true. There are chips where the radio DSP cores have their program loaded into main memory and it's unsigned. You talk to them with mutexes and shared memory pages. There is also no legal basis for requiring radio controllers to have signature enforced firmware loading. He's being sarcastic. It's think of the children but with electronics and PII.
There is also no legal basis for requiring radio controllers to have signature enforced firmware loading. If someone actually tried to write their own radio firmware and made a mistake, there very soon would be. Messing around with radio transmission is not a game. Make enough noise on the wrong frequency and now you're interfering with communications for emergency services responding to a disaster or air traffic con…
The FCC hasn't cracked down - yet. As other have pointed out that is probably because they don't see a widespread problem and so the politics aren't worth it. I'm sure someone reading this is involved with radio, I hope they take the warning (I believe their response will be a form of we already know)