Stuff like this is always possible wherever you have fully centralized architecture. I don't know how many massive cloud failures it will take for IT community at large to realize this.
That's not very fair to a company that was one of the pioneers of a lot of the things we consider normal on today's software as a service.
Also incorrect, they have great cloud and devops practices. If anything it's likely this bug's impact would be limited due to how decentralised SFDC operates.
Still a massive fuck-up, I'm interested in seeing if they'll release any more detail on why it happened.
While a little unfair, and Salesforce is a decent product with nice dev tooling (apart from the weird ancient Java ish custom language), but under the hood, it really is just a Oracle database per org.
In fairness they did do long enough ago that they would have massively messed it up if they at least didn't understand something about running software.
SFDC hate is pretty common, maybe because of how big they are. I think that their tech is actually pretty impressive.
Other than being pretty public at this point, this incident could have easily happened in an upgrade/rollout in on-premise settings as well (at least without a good staging environment and test process).