Earlier quoted context omitted.
Purism is never going to end up with fully open source baseband firmware. It's not going to happen because the radios are subject to several regulations which means customers can't be able to modify that firmware. There's going to always be a trust hole.
People should push for open source as much as possible. At some point it will be easier to lobby for the new regulations when everything else is fully open source. See also: https://forum.pine64.org/showthread.php?tid=11815
It's very different than if I modified the firmware on my hard drive or UEFI on a PC. I might fuck up my stuff but it doesn't affect you. I can fiddle with my hard drive firmware all day but I'm not going to block a 911 call you're trying to make.
Also a company giving out modem firmware is an exception and not a rule. It re-classes the device as a hobbyist/experimental device and if they go traipsing around with it they could potentially face fines (unlikely but possible).
Again it's not about lobbying it's about a limited spectrum and people being stupid/assholes not realizing or caring their pocket radio affects others. You live in a world where shitheads try to make their cars louder on purpose and you can pick up dozens of WAPs because everyone sets the power to the highest number the interface allows.