A few big points to make here -
Yes, "Rank THEN Rate," not "Rank NOT Rate." Otherwise, why would articles like "The Value of A Tenth" have any value in the judging community? Additionally, again, the rubric system exists to put a number on a performance, irrespective of the competition. If we were talking about a BOA show, then I would agree with you that the numbers aren't quite comparable. An activity like DCI where corps are adjudicated over the course of a summer in a high volume of events allows for the numbers AND rankings to both mean something.
Secondly, if the numbers have no basis, why do all your posts about the OC standings include numbers? They should really only be grouped by who has beaten whom, when, based on this logic of rankings only matter. Doesn't seem like that would make a lot of sense.
Also - people wouldn't freak out over partial recaps is rankings only matter - because the information in there would be worthless. Why put a number on something if we aren't expected to analyze it scientifically?