[NullPrefix]

>How about the software in my satellite internet radio transceiver (one rogue transceiver could take down the entire beam/jam the satellite)?

This sounds like a failure on the satellite part. Can you do satellite comms with SDR?

>How about the software in the micro controllers in my car? Should I be allowed to modify that code too (if I mess up people could die)?

What if people die because you cannot modify that code?

[umvi]

The problem is physics. You have a bunch of people in fairly close geographic area transmitting to the same point in space on the same frequency band. One bad actor can interfere with everybody else's tx.

> What if people die because you cannot modify that code?

I think it's far better to trust unmodified safety critical code that's been tested than to trust Joe Blow's precariously modified braking code that allows his Honda Civic to drift around corners better.