Maybe a better way to put it is that backups are isolated from current "production" data operations.
Backups are not invulnerable, so yes, it's still possible to overwrite the backups, but that involves engaging the backup system specifically. Just doing file operations or settings changes on the production system won't do it.
Dropbox is not isolated from production data operations. In fact the whole point is to synchronize production data operations as fast as possible. That makes it dangerous.
(This does not excuse the bug is this story; sync setting changes should be obviously be atomic transactions that are confirmed on the server.)
Backups are not invulnerable, so yes, it's still possible to overwrite the backups, but that involves engaging the backup system specifically. Just doing file operations or settings changes on the production system won't do it.
Dropbox is not isolated from production data operations. In fact the whole point is to synchronize production data operations as fast as possible. That makes it dangerous.
(This does not excuse the bug is this story; sync setting changes should be obviously be atomic transactions that are confirmed on the server.)