You can probably count on one hand the number of people who care where a specific Cessna 172 is at any given point in time. What's contradictory about that?
If nobody cares where a Cessna is, why is it mandatory that everyone can find out? You could count on a fingerless glove the number of people who care where my car is, but I'd prefer not to stick that information in a public database. Some percentage of Cessna pilots prefer to keep that information private, and the rest can continue sharing that information regardless, so it would be a strictly positive-utility change. For what reason, other than the fact that Cessna pilots are a tiny minority, has this not been changed yet?
"flying is a privilege not a right", "you have no expectation of privacy in public," and "but we're safer from aircraft collisions etc and that justifies the reduced privacy" are what it boils down to. I'd be shocked if anything you here isn't a nuanced or refined way of saying one of those.
Life is a lot safer now, so ever more 'safe' things start to look dangerous. If you prefer liberty/privacy to safety you're quickly becoming a dinosaur and if necessary society will imprison you to make sure you don't interfere with democratic process of the majority.
In the UK, people who are annoyed by GA plane noise will look up the owner’s details (these are held in a mandatory, public database by the CAA, equivalent to the FAA) and contact them directly.
In Germany the aircraft registry is not public. But that's only a minor advantage. People who would need to look up my aircraft registration aren't usually interested when or where I'm flying. People who know me are interested. And they know anyway. Can't hide the license plate of my car from neighbors, can't hide the aircraft registration from family and friends.