You are neglecting the value of your time here. If you have photos, videos, or other information that accumulates often, going to the bank on a regular basis to sync your drive to your computer sounds like WAAAAY more hassle than just paying $10 a month on Glacier. Assuming it takes 1 hour a month to back up your info, in order for it to be worth it, you would have to value your time at less than $10/hour, completely discounting the cost of the drive.
Yes, you have a good point on the inconvenience of regular syncing...but I guess my use-case for Glacier would be for files that do not need to be regularly synced.
For example, as a photographer, I have roughly 1.5 TB in photo files. The vast majority of these I will never need to access again because the ones that I've liked, I've either stored in other drives (for example, a small drive of wedding photos for my portfolio or for recent customers) or on online services (yes, I know this is a cost in addition to the external drive, but I was using these services already, and for reasons other than just storage).
So for me, Glacier would be a place where I dump a chronological store of photos, a first-in-last-out kind of system. There's no need to regularly sync any of these photos. There may be a need to go back through certain folders years from now if I decided to compile something for a family album or something bespoke like that. And for that reason, it's necessary to have a last-resort store for these files.
So if I have 1TB of files that need to be rarely accessed and never updated, it's hard to justify spending that on Glacier (assuming I have a pretty safe external place to store this drive). At the rate that I accumulate files, it should only take me about an hour a year to backup photos. (plus the time it takes to find the hiding place for the hard drive).
Actually, even in your use case, the cost of glacier (or some other service like http://bit-chest.com/ ) is justified. However, you have to see it as a kind of "fire insurance" for your files. Even if the total monetary cost, computing time and materials that you use to store the files yourself is probably a lot smaller than putting your files in Glacier, what you get from Glacier is that the files there are SAFE. Eleven nines safe. No worries about burning houses, earthquakes, storms, flooded data centres, just safe. Getting that degree of safety would be hard to do on your own, and probably push your costs into similar regions as the ones that Amazon offers.
