All software has a user, otherwise, what is the point of having the software in the first place? A server’s user is an operator, devops, or whatever the org calls it.
Not all software has a user present when it runs that can make decisions like that. Probably the vast majority doesn't. If an automated update process that runs on thousands of servers encounters an expired certificate, it's not like it can pause and pop up a prompt to ask me if it should continue or not. I do a lot of immutable infrastructure and don't even have shell access on those machines, so even if I wanted to, it wouldn't be possible.
This seems pretty easy to mitigate if someone created a IGNORE_EXPIRATION environment var where any matching cert fingerprint would ignore the expiration date. I have a feeling the more paranoid people would hate it, but it’s better than what we have now where it’s all-or-none ignoring cert validity.
