A home user is fine with a 3.5-4 hour window before their backup becomes available for download (as it will probably take them days to download it anyway).
In a corporate environment, I don't want to wait around for 3.5-4 hours before my data even becomes available for restore in a disaster recovery situation.
Seems good for archive-only in a corporate environment (as the name implies).
In a true disaster recovery (Building burned down or is otherwise unavailable) - it usually takes most businesses a week or so just to find new office facilities.
But - agreed, there will be some customers for whom Glacier wouldn't work well for all use cases.
Now - a blended S3/Glacier offering might be very attractive.
Does this satisfy the legal requirements you mention? I assume there are further requirements on what constitutes sufficient encryption?
I am guessing you work in a company with a good IT department then, I am guessing this is not the average. Many companies I have worked for 4 hours would be a miracle with a 1-3 day operation minimum.
And don't forget that the X00MB type size limits many IT departments puts everywhere it not because getting a TB hard drive is cheap, but because all of the extra backups add to the cost of each new MB. Having another extremely cheap way they could backup large amounts of data (encrypted?) would help to reduce the cost of each extra GB.
In that case, 3-4 hours would be more than acceptable.
ding!