I like the explanation that simply explains "privacy":
When you are going to the toilet, and everybody knows that your going and what you'll do there, but you still close the door (for the most of us, most of the time).
Like when you’re in high-security areas and have to be monitored in the bathroom there might be a door between you and your guard but no real privacy.
Or when people loudly object to strip-searches at the airport but the scanner that sees everything but then only shows a cutout highlighting suspicious areas to pat down are mostly fine.
It's also helpful as we can notify you early if you have some undiagnosed medical issue. You could unknowingly spread your illness to your children without this early detection. We're even able to reduce your monthly health insurance premium by providing this data to the insurance company!
This also enables us to find troubled Individuals before it's too late and address building drug issues before they're full addictions. We'll be able to get them the required attention they need to get back on their feet and be productive members of our society. (Maybe not here though)