I really hate "incompetence" as an explanation for anything, but especially something as complex as software and security in particular. Obviously, it's easy to blame a single person as incompetent, but the reality is that their work was certainly part of a team effort. Are all those people incompetent? They were using Azure, which presumably didn't warn them well enough, so are the Azure team incompetent for deploying a dangerous application? Clearly the technical authors who wrote and reviewed and published the Azure docs did a bad job of explaining CosmosDB's security model. If these Fortune500 companies employed a security team to test and audit their cloud apps then they missed the problem too. Or maybe they didn't, but some manager or product owner didn't read the report properly, so that security team were incompetent for failing to report the problem well.

This is how everything works in pretty much every industry. There are layers upon layers of complexity in everything, and no one has enough oversight to take full responsibility for some mistake that occurred somewhere down the rabbit hole.

Somewhere, somehow you could probably call someone's mistake incompetence, but doing that relieves everyone else of their little part in developing a chain of tools and applications that enabled that incompetence. If we heap all the blame on a single individual then no one else has any reason to improve it. We can just say "OMG, Chris was terrible! I'm so glad he's been fired now everything will be perfect!" until the whole sorry mess happens again.

Instead if we accept that mistakes are inevitable, and we accept that anyone can make one, then we're driven to build systems and processes that include guards against mistakes. Applications that check and validate things automatically, even if it's hard and expensive. That's how you get to robust software that doesn't fail like the thing in the article. Blaming individuals will never get you to that point.