I’m not suggesting they can and don’t know enough about the privacy implications to say one way or the other. I’m suggesting that most people don’t care, and it’s the best option available while giving them the UX they want and possibly as close to the privacy and security as possible. What you suggest means that literally anyone with an iPhone (myself included) has compromised their keys and thus it doesn’t matter. So it makes no sense to not allow that option for people. If they get burned, they will suddenly learn a lot about keys and security.