S3 does fail safe. The default is to deny access, but the problem is that every so often someone “solves” a problem by granting access broadly rather than learning how the tool works or reading the prominent warnings. This isn’t like C++, it’s more an example of how people don’t consistently respect the ancillary tools they use enough to learn how they work. I’ve seen the same pattern in many other contexts and it always came down to “I need to get my real work done, I don’t have time for this sysadmin stuff!”