The good news is that the device is owned by me and under my control. However, since it's just a test machine with no personal data—or so I believed—it's less protected than my other devices. For example, it has a weak login password, no Filevault, and no biometrics (Mac mini).
In general, the presence of my passwords in the cloud is an unwanted and unnecessary liability for me. I understand that for other people, cloud storage is a benefit, and I don't wish to deprive them of that choice. Nonethless, Apple deprived me of a choice in this case.