rfkill is the worst piece of software ever conceived, in a nutshell it is designed to completely destroy radio (eg. WiFi / BlueTooth / etc) right when you need it most. Why anyone would think that you would need to do this is beyond me (I'm not buying the "it uses less battery" argument, using a shot gun would be more elegant). Whoever though this needed to be installed by default in all Ubuntu distro's needs a mental health plan.
After dealing with years and years of agonizing pain because of this I found an elegant solution, remove it:
sudo apt-get purge --auto-remove rfkill
No more USB cables, booting Windows, and command line ninja mastery, this works! Even if you accidentally hit that mysterious checkbox in NetworkMananger the radios do not die.
I'd also like to thank the genius who though it would be a good idea to add "connect" buttons to network connections in the latest version NetworkMananger, you are a true visionary!