CISO: https://cio.ucop.edu/spotlight-patrick-phelan-once-a-ucla-br... I can't think of any reason not to use a cloud hosted service for backup today. OneDrive, Dropbox, and Google Drive all sign BAAs and give you versioning amongst a million other security features. AWS even has offerings that let you take periodic snapshots of on-premise volumes. Point in time recoveries for the entire account would be nice add too…
There are reasons not to use cloud services for backups, not trusting them with your data being a major one. But then you should still be using some kind of internal backup system. There is no excuse for not having backups.
This attitude leaves the victim paying millions in ransom. Look, Microsoft and Amazon probably have a better handle on security than your IT dept which is two people who also have to fix any issues like the WiFi not working or software not updating.