I agree, take-down defense is a ridiculously undervalued skill in MMA scoring.
In a cage, it's much much harder to stuff a take-down than it is to complete one. Even if you can't shoot a fast double you can always drive them against the cage and get it from there.
I think judges confuse the cage pummeling with Randy Couture style clinch fighting. Let's say in JDS vs. Nelson, Nelson went for a takedown quite a few times and the couple of times Cigano couldn't shuck him off quick, Nelson had him temporarily pressed against the cage.
In pummeling, JDS was winning that exchange because he was stuffing the takedown. But from the judges perspective, Nelson was holding him against the cage, therefor "octagon control."
We need some judges who understand wrestling.
sig credit to Limba