Board Thread:Lore Discussion/@comment-83.84.138.71-20131231144655/@comment-4705438-20140107031920

There wouln't be much reason for the Dwemer to make Soul Cairn. They we're not exactly fond of magic and we don't see any traces of their technology in there.

My personal hypothesis... If you believe the books, that might as well be Imperial progroganda, Ayleid used to be huge fans of the Daedra. They are also known for their skill in enchanting, crafting of Welkynd and Varla stones.

So it would make sense. Something really old, and willing and able to trade souls to more powerful entities.