Board Thread:Lore Discussion/@comment-25443668-20140921053510/@comment-24.185.108.132-20150218191443

Because the act of participating in the creation of Nirn greatly limited their ability to project their influence: they lost part of themselves making the world, whereas the Daedric Princes did not. Because they participated in creation, they're also bound by the beliefs of mortals, which as per Aka/Auriel/Alduin/Akatosh/etc., can result in fracturing and the divine equivalent of insane schizophrenia.

For the Aedra, belief is a very powerful thing. Akatosh literally only came into existence because of the Marukhati Selectives, a mortal endeavour which created the man-friendly Time Dragon/Patron God of the Empire. Compare this human-friendly Time Dragon to Auriel, the Elven counterpart that led campaigns against man. You have two shards of the same Time God actively conspiring against each other, because of what mortals believe.