Though considering them separately, before the Aedra were recreated by myth, they were just a group of et'Ada like any other. They decided to cut parts of them self and create a new world, but a decision like that doesn't change what something is. The Daedra had the same abilities but chose to do it in another way.
I understand your point perfectly, I just disagree. The way I see it, the creation of the subgradient that is Nirn, the "attributions share" and the sacrifice of self all just differentiates them considerably from the Daedra; Mundus isn't the center of the egg/wheel while the daedric realms aren't for no good reason... daedra are just part of the system, mortals can escape it...
Though this discussion touches on a more fundamental qeustion, what is an Aedra? If the Daedra got together and build a world, would they also be Aedra?
Well, apart from that they wouldn't; if they went about that building of a new world in the same fashion that the 'Aedra' did then I'd say yes (well, they still wouldn't be 'Aedra' in the 'our ancestors' sense from the perspective of Nirn, but from completely outside they would be the same). Though I'm not sure what effect that would have on the universe, I'd reckon it'd screw it around royally... But since they haven't and they wouldn't, it doesn't change anything, they don't want to be like the Aedra...