Thanks for the summary. To respond to OP, no I don’t think this is the best explanation. The people who usually say they don’t care about privacy because they have nothing to hide are people who don’t care about surveillance either, so that doesn’t exactly change their minds.
The best way to make them understand is to provide examples that may affect them directly. And I’m not talking about the “show me your phone” or “leave your bathroom door open” response, because that’s not a good example of mass surveillance that we are trying to explain to them. It’s hard to find the best comparison, but one example is home cameras and baby monitors. Those things are so insecure that anyone can access them over the internet. So we ask them, are you fine that any rando on the internet can tap your living room camera and watch you even though you’re just watching tv and not really doing anything private?