You probably don't want a system where all the hardware and software for controlling mobile radios is readily accessible to and modifiable by anyone. You might think you do, but the first time you try to call an emergency service and you can't get through because one idiot somewhere in range of the same base station has screwed up his debugging code and jammed a control channel, you'll change your mind.

I've been the guy who drives around in a truck with a lot of mobile scanning equipment to try and figure out where the rogue device is. There is no magic button like in the movies, where they can immediately triangulate the source of the interference to within a 5 cubic metre box. You basically have to rely on simple physics and boots on the ground. The device you're hunting for isn't playing nicely, so any assumptions you could normally make based on things like which base stations it's in contact with won't necessarily be valid. Things are a bit smarter in modern networks than they were back when I worked in the field, but physics is still physics.

In short, there is a legitimate justification, born of experience, for every telecommunications regulatory authority in the known universe requiring this stuff to be certified before you can legally use it. This is also why in some jurisdictions agents acting for telecommunications regulators have certain legal rights to access private property.

Of course this only affects the radio equipment. I see no reason it should be necessary or possible for such software to have any control over other integrated peripherals such as cameras, speakers, microphones or local storage. And the primary concern is people who could modify the code and break the network, not preventing any legitimate audit to prove that devices are only doing what they say they're doing.