I fully agree. This my pov as well. The expected codigas were told by number of instructors that I thought it must be common for AT instructors to make it part of teaching. Most of the so called codigas are majorly about the floor craft. The other is about Cabaceo. First time I saw them listed out on a post card was many years later. At first I chuckled about having to put the obvious in writing. I assumed everyone knew it. Apparently not.I can see how this might differ from place to place in its details (dress, for example). But we all know that the basic format of a milonga is the same throughout the world. The cabeceo is not some ancient mystery, it's simply an extension of social behavior. They are not being followed for the reasons stated above: people are aware of them but choose not to observe them. Some folks are just thickheaded, others don't seem to care much for the craft or technical aspects of the dance floor. This, as has been stated, does not only apply to beginners.
Unlike other social dances, AT is a traveling dance. That alone requires consideration for others around you in the line of dance, that isn’t an issue in the other social dances.