I just spent a good few hours on the Dreadnaught opening a grand total of 274 chests, and got 20 Reciprocal Runes. I'd imagine most people don't grind/farm for hours everyday just to get something so simple, and probably run out of runes pretty fast. No level one runes = Can't charge the level two runes. No level two runes = Can't charge the level three runes. No usable runes = No reason to go to the Court of Oryx.