Haven't read into this too much, but I think the affected person that made this get attention was a solo dev that was prototyping a solution for one of his customers.
And the reason he raised a stink was because he had a huge bill, as the name he chose for his bucket was by chance the same an open source project used as a sample bucket name, so whenever someone deployed it without first customising the config, it was pinging his bucket and getting a 403.
I believe that the trick is not to show the developers the bill.
I haven't had access to the AWS bill in 4 of 5 companies that I've worked at. Why? Fuck if I knew, but I got vague answers like security and compliance when I asked.
I wonder how many thousands could have been saved if all devs could see what they're actually paying for but not using.
They show us the cloud bills at my work. It's a sobering moment when you see the monthly price tag for your team's development work.
I'm not saying it's not justified or that the company doesn't make up for that cost many times over but it's very useful to have a real world reference.