It is not a theory, it is my opinion that justifies all the known facts about Enma.
I would not dare to say that I have the absolute truth, I am not as bold as you and your kind. However, between an opinion that justifies all the facts and an opinion that goes against most of the knowledge we have, I think it is easy to distinguish which is objective and which is not.
As I said before, an opinion to be acceptable must justify everything, not just one thing that is convenient for us.
To say that Enma has Oden's Haki implies that Kitetsu (Oda) has lied to us, implies that something never seen before has appeared, nor mentioned as objects with other people's Haki... Which basically makes the narrative and the work a poop
The survey is perfectly valid. This is about Oden's Haki, not if Enma is a magic sword. Which by the way, has little magic because we know how it works, we know how it was created and we have been knowing about "cursed" swords for more than 800 chapters.