I dont think the tales of Marobar Sul should be used in any way to understand either the Dwemer or the Daedra.
In Morrowind it is clearly stated that these are not Dwemer folk tales at all, rather Dunmer folk tales given a 'Dwemer' look by the author.
They are fairytales and should not be used to try and understand the Dwemer or Daedra.
Many of these cautionary or amusing tales exist in our own culture, but no student of mythology would seek a deeper understanding of Jesus by reading the tales of the brothers Grimm.
I think though that Vivec's account has the ring of truth: "And no sooner than we had completed our rituals and begun to discover our new-found powers, the Daedra Lord Azura appeared and cursed us for our foresworn oaths. By her powers of prophecy, she assured us that her champion, Nerevar, true to his oath, would return to punish us for our perfidy, and to make sure such profane knowledge might never again be used to mock and defy the will of the gods. But Sotha Sil said to her, "
The old gods are cruel and arbitrary, and distant from the hopes and fears of mer. Your age is past. We are the new gods, born of the flesh, and wise and caring of the needs of our people. Spare us your threats and chiding, inconstant spirit. We are bold and fresh, and will not fear you." Then the Chimer are suddenly transformed into Dunmer, though Azura claims it was the Tribunal's fault.
. . . "And Azura left us alone, in darkness, and we were all afraid, but we put on brave faces, and went forth from Red Mountain to build the new world of our dreams." [From "The Battle of Red Mountain"]
Azura can be seen like a murderer screaming "Look what you made me do!" You are her puppet in "Morrowind" just as you are Almalexia's puppet in "Tribunal". But the Nerevarine eventually cuts his or her strings and leaves for Akavir.