I guess you're right in your implicit suggestion that aerobic climbing is a waste of time (at least for some climbers), but for the wrong reasons.
some interesting reading below. Especially these two pages but also others on the same blog.
on another note : in at least a couple of interviews patxi usobiaga says that he starts his training season with a low intensity-high volume phase (aerobic training...all-day climbing at boringly low grades for him, 7 days a week) and that this is crucial as a foundation for the equally extensive strenght and anaerobic endurance phases that will come later (double daily sessions)
some googling on endurance sport periodization (eg swimming) might help you figure it out a bit better.
some common sense will also make you figure out why all of this is not that relevant for the average amateur climber, as long as overuse injuries and overtraining are not an issue.