Why not? What if people want to break in to your house and use your data to get to know your routine? Of course, you are not the specific target. But it should not be too hard to set up a criminal organization around information left online about people's whereabouts.



What about people who intend malice? Sure, not embarrassing yourself is one thing. But there are things like identity theft.



What is your argument against it.



Clear.



An internet detective?



Of course, it was just an example. But it's basically intended as a way to show that while current owners of a vast wealth of information may be benign, future owners may very well not be.
I'm always reminded of the Jews that were registered with a synagogue before the outbreak of WWII.



Do you know how much it costs to retain that much data? Do you know who will pay for that?



I doubt that it's the babbling that they'll be interested in. But e.g. the Stasi killed people for making bad political jokes. They shot them in the neck.