IMO, there's plenty of blame to go around, however the onus really should be on the individuals that are making the decision to go on Amazon and trust that there services will always be up. Unfortunately, some people don't know, so they will just blindly choose Amazon for their name recognition.
For the places that truly care about reliability and have the technical staff to make informed decisions, they should understand the limits of reliability with various architectures. As I mentioned before, one of the tenant of reliability is isolation. When the scope of isolation is increased (e.g. single host vs multi host), one must also handle failures at that scope. Amazon isolates at the datacenter level. So should those utilizing Amazon's offerings.
For the places that truly care about reliability and have the technical staff to make informed decisions, they should understand the limits of reliability with various architectures. As I mentioned before, one of the tenant of reliability is isolation. When the scope of isolation is increased (e.g. single host vs multi host), one must also handle failures at that scope. Amazon isolates at the datacenter level. So should those utilizing Amazon's offerings.