Be careful, she is a "Man-Eater".

Not for everyone. Stupidly throwing myself out there as an example, I have never been interested in BDSM or its subcategories (that explanation might also assume it's only a furry thing, too), but any reason I give from experience or appeal will only be rationalization, too. It's just 'there', so-to-speak; you won't 'understand' a fetish/paraphilia except by already having it. Vore, like other fetishes, also has subcategories that some people like or dislike even if into vore in general just because the reason for their attraction to the fetish in general varies for the same reason that I and someone who came to it from BDSM wouldn't be into it for the same reason.

All I can say is, through a combination of childhood predispositions (like early exposure to the exact material), pornographic escalation, and the old "neurons that fire together wire together" principle, anything is possible. That goes for any fetish/paraphilia it seems, but unfortunately, you won't find much good research on the topic for how controversial and taboo the subject of them are.