I can think of many people who would like this feature. Not techies, but the sort of people who realise they need backup of some sort.
Anyone thinking this feature is in any way a backup solution is really, really stupid. No, cloud storage is not a backup solution if it is synched to local storage; it only means that when you delete stuff by accident, your data destruction orgy is replicated on the cloud as well. Same thing goes for those who think RAID is a good backup solution. It isn't.
Backups store data in another media, and that media is usually not insta-synched with the changes in the main storage system. Because backups are used when you fuck up on the main storage system...