UPDATE 20TH APRIL 2015: I'm going to try and expand this to bring in other characters as well. I have edited and added to this below. Once it is complete-complete, I'll post it as a proper essay.
I was browsing through the Sailor Moon tag on Tumblr and I just happened to come across this confession:
I thought Kaitou Ace was awful and creepy, a borderline villain. Why do so many people want him together with Minako?! [Link]
Ace Kaitou was very sinister, creepy and disturbing... and that’s what makes him interesting. Unlike the Shitennou in Sailor Moon, who had their duty and memories warped and removed, Danbur