So you trust Glacier or Google Nearline (or any similar provider) without testing? No testing ever???
I wouldn't feel happy with my critical data floating around in the cloud, without my checking it at least once a year to make sure it really exists.
And once you do start verifying that data, you will incur all sorts of charges to access it.
This allows you to trivially share, copy, move and retrieve that data quickly as well as fully control who has access and when.
I am sure there are use cases for this but in a situation where you have petabyte scale data, it is often the case that you also have the infrastructure to save it. How many places would need to store >5tb of data a week that
* don't have this capability in house
* will almost never need to access it again.
* will not need it in a timely manner, if they do need to access it again.
* don't have the money to implement their dedicated server and storage on site for this purpose.
I am not saying that this rules everyone out, but the prices are so low, and tape must be so annoying, I couldn't imagine why they keep offering this. Obviously, some peopel must be using it but in 2016 with storage prices being so low already, i don't know how many places have this amount of data and meet the above requirements.