Are you implying governments have historically quarantined healthy people who have NOT been exposed, like they are doing now?
There are certainly times that has happened in history, although it's somewhat unusual.
But the thing is, that is not what is happening here. People are not being quarantined if they haven't been exposed.
The people who are being quarantined in this case are people who have been exposed. They are either infected or close contacts - close contact is the term used for a person who has been exposed.
Nobody is being quarantined in Australia unless they are either infected themselves or have been exposed. And that isn't an unusual or unprecedented approach.
As I've said, I'm certainly not convinced COVID is serious enough to justify this approach, but that is a different issue. And people can argue that without any need to rewrite history.
(Note - I would not absolutely rule out the possibility that there have been some individual cases where mistakes have been made. But it certainly isn't policy that people who haven't been exposed are supposed to be quarantined, and the woman in this case certainly seems to have been a legitimate close contact).