I don't think it is literacy really, just sloppy engineering process. Typically this happens when someone develops a service which is front facing without any

I don't think it is literacy really, just sloppy engineering process. Typically this happens when someone develops a service which is front facing without any proxy/ LB before it, goes to production and gets validated IP and other logs are great everyone moves on . Few months/years down to scale their service or improve security a LB or CF type proxy is put in front and no bothers to check the IP logs are still valid because no one actually uses IP for anything in their tooling( like filters/blocks or geomapping etc) so won't notice the break at all.