Comment by ajb

Ideally a backup system should be implementable in such a way that no credential on the machines being backed up, enable the deletion or modification of existing backups. That's so that if your machines are hacked a) the backups can't be deleted or encrypted in a ransom attack and b) If you can figure out when the first compromise occurred, you know that before that date the backup data is not compromised.

I guess some people might have been relying on this feature of borgbackup to implement that requirement