I could get on board with this. I do not ship Elena with either of the Salvatore brothers because, frankly, they both annoy the hell out of me. Elijah however is very intriguing. He's capable of great violence like you'd expect a vampire to be but he's not pointlessly killing people, running around ripping open necks for the hell of it. But he also seems to have a lot of self-awareness; he can reflect on himself without becoming a preachy drama queen. I think he and Elena have an understanding of each other. I think she appreciates his strengths as a man and sympathizes with his flaws (because in a lot of ways they are very similar to her own). Meanwhile I think Elijah appreciates her ability to be compassionate and feel remorseful over even the most justified of acts.
The distance is from his kind of courtly aloofness and the very clear boundaries between them establishing their relationship as completely platonic.
It's interesting because I agree that they've established a platonic relationship because Elena of course doesn't see him that way and while Elijah does see her that way
, he won't press the issue. I saw a comment that the actor Daniel Gillies (?) made about how Elijah wouldn't make a move on Elena unless she somehow signaled that she was interested. How refreshing!
Also, I liked Elena best during their scenes/episodes in the second season. I thought she was her most pro-active and least tolerant of Salvatore bullshit then. That's when she reminded me most of her season one self.