You haven't read how it works have you?
Once activated it searches not only for any local user data but for any attached storage over the network, cloud or USB and encrypts that too. Bang go your backups.
So basically once you've got over the hurdle of setting up an automated backup for the customer, cloud backup for offsite you also then need to setup and volunteer someone to do a manual backup and remember to unplug the storage. Sorry Miranda or Cheryl!
I'm sure you could come up with something more sophisticated but these are normal people with average aspirations and better things they want to do in life. Hence why I just use Cryptoprevent.
Vaccine rather than cure.