I don't find that I expect more privacy at my home than when talking to someone at work, or while walking in a park. I'm aware that someone can overhear in public, but I'm not constantly aware that a microphone is following me.

And in many places, people take their phones out of their pocket. And women's pockets often don't have good pockets at all, so whenever they sit down the phone is also put down (or in use).