Of course its a bad idea to rely on a closed platform. Except that the majority of people rely on closed platforms (Windows and iOS) to communicate all the time. MS could prohibit pirate bay links on windows using the automatic update system; but they probably wont't.
You have to use software that people are actually comfortable with and operate within that ecosystem. At the moment Skype may well be the best bet. Try finding another piece of software that has end to end encryption and is widely adopted by non-geek's.
You have to use software that people are actually comfortable with and operate within that ecosystem. At the moment Skype may well be the best bet. Try finding another piece of software that has end to end encryption and is widely adopted by non-geek's.