I don't believe in the cloud as the one and only thing to solve backup issues, I believe in the "all the above" method. Back then, if you were doing a master thesis, you would make copies and backups and backups to your backups on floppies or even CDs. Nowadays, you can use a flash drive, someone else's flash, PC, or external hard drive or even their email, your PC, an external drive, NAS, cloud storage, email, CDs, DVDs, even floppy drives. If you know what you're doing and have the hardware, going to the extreme, making tape backups of said master thesis paper. The cloud is just one solution out of many. I personally know a few people that have lost their digital tax documents that were on their hard drive on year, lost the next year on an external hard drive, and now they're using a cloud service.
It's about finding the right balance and the ideal solution of cloud and local storage.