In a corporate environment, I wouldn't want to depend on the cloud as my primary backup solution in the first place. I'd be much more comfortable using it as the offsite mirror of an onsite backup. If you're at a point in disaster recovery where you have to restore from your offsite, you (likely) have bigger problems than a 4-hour wait time.
I personally believe that data should never be deleted (or overwritten), but only appended to. Kinda like what redis/datomic does. So, keep live data onsite, along with an onsite (small) backup, and all the old data in Glacier.
You can believe that, but legal realities dictate otherwise. There are certain classes of information that you are not permitted to keep beyond a defined horizon, either temporal or event-based. Legal compliance with records management processes means having the ability to delete or destroy information such that it cannot be recovered. Note that if the information is encrypted, you can just delete the decryption key and it is effectively deleted.
That's just the beginning - if you've ever been in a ediscovery process, having large amounts of historical data is actually a liability - if instead of 100GB you have 10TB, you'll need to hand that over, and before that, to cull it so you don't inadvertently hand the opposition a huge lever to be used against you. Processing and reviewing 10-100x the data can take inordinate amounts of time more than you expect.
