This isn't a "cloud failure". All of these apps would be running now had they spent the additional 5% development costs to add failover to another region.
us-east1 is supposed to consist of a number of "availability zones" that are independent and stay "available" even if one goes down. That's clearly not happening, so yes, this is very much a cloud failure.
It's an AWS failure, perhaps, but it's not a reason to write off "the cloud"
It would have to be catastrophic for most businesses to make think about escaping the cloud. The cost of migration and maintenance are massive for small and medium businesses.
Probably, but they're usually dropped after they come back up
Depends how small.
I have clients and I’ve heard “even Amazon is down, we can be down” more than once.