"The freedom to study how the program works, and change it so it does your computing as you wish" is incompatible with the security and proper functioning of th

"The freedom to study how the program works, and change it so it does your computing as you wish" is incompatible with the security and proper functioning of the cellular RF spectrum. Other people want to use the airwaves, too. In fact some people have come to rely on the availability of voice calls such that it would be a Very Bad Thing if an amateur's typo took out voice and data for several city blocks. Also the carriers will never in a million years authorize people to transmit as they wish on cellular networks. The radio firmware, at the very least, has to be closed source.