No, they didn't. Large portions of AWS's documentation details how you, the developer, are responsible for using their tools to engineer a fault-tolerant, highly available system. Everything goes down. AWS promises varying amounts of nines everywhere, not 100%.
S3 is not the cloud, it's one system running in the cloud. The cloud is not down, S3 and services dependent on (and possibly related to) it are.
One of the selling points of the cloud is that dynamically provisioned services from multiple providers enable engineering fault tolerant systems that are relatively secure against the failure of any single backend. But, yeah, if you are dependent on one infrastructure vendor's service -- particularly running in one particular region/zone -- you are probably better off than running on a single server for reliability against failures, but you aren't anywhere close to immune to failures. I don't think even cloud vendors have been particularly reluctant to make that point.
Well good thing I have my backups on [some service that happens to also use S3 as a backend].