This conclusion "The cloud is just a .. blah blah blah" is weak: Amazon offers isolated availability zones within each region to mitigate this risk at the system level, it gives you the ability to take EBS snapshots that you can backup on S3 (with 11 9s of durability), and scaling features you just will not find on "just another computer." And you are meant to architect to this with multi-AZ designs.

It's managed infrastructure not some miraculous alternative universe where probabilities do not apply to you.

From the docs:

"Amazon EBS volumes are designed for an annual failure rate (AFR) of between 0.1% - 0.2% ..."