They've been this fragile for some considerable time. We've just been lucky, over and over again, that nothing of this seriousness has happened before.
Now that a major worldwide outage has happened I'm curious what industry changes will take place going forward... If any...
One might say, well there was this huge outage, but in reality they will keep doing as they've done business as usual. They may spin up a new shell company, under a new name, and that will be far cheaper than devoting a budget to security in the first place. Rinse and repeat.
There has long been little to no liability for software flaws, and proving negligence is an uphill battle.
Just to clarify, System's Engineer's know how to build resilient systems that do not fail under most circumstances. It is only when corporate overlords decide to make the tradeoff of resiliency, for a little more penny pinching in the shares; that things like this happen.
It is a natural flaw of any centralized hierarchical system involving people. Corruption, Front of Line Blocking, are all just another term for Single Points of Failure.