Re: But....
"Deploy in the cloud by all means but still backup, replicate, ensure that you don't have a single point of failure."
Unfortunately, that is what they've done. This fault affects a specific region, each of which contain multiple availability zones. Each zone constitutes a logical datacentre, comprising multiple physical datacentres (between 3 and 6 in each AZ, I believe). Deployment across two or more AZs in a given region *is* removing the single points of failure. Supposedly. Didn't work this time.
AWS don't particularly recommend deploying across more than one region, because each region is effectively a completely different cloud, common in branding, usage etc, but connected only via the public internet. Replication between zones within a region is fast and free, but replication between regions is slower and costs.
Ultimately though, a well-designed AWS deployment, consisting of all the fault-tolerant bells and whistles, still has no upfront cost and is thus way more achieveable than doing it on-prem. Said bells/whistles will make nuclear outages like this the cause of the rare downtime you do get.