maybe it just means those a pretty worthless certs focused on training you to shill for cisco instead of teaching you actually important network concepts...
No, it means I didn't spend any time on a random specification that will rarely be seen in a production environment. I feel I gained a lot of networking knowledge.
Not sure if you can call it “rarely”; it is very common in application programming. But it is never sent over the wire (unless there is some very buggy IP stack somewhere), which is probably why you did not encounter it in entry-level router/switch certifications.