Yes, it is a combination of her being an actual main character (the player character) since Rule of Cool dictates it is better to involve the player than strive for realism overall, as well as camp in that the story is meant to be a half-serious fantasy world. Yet despite that, the game designer has included a silly yet fairly airtight basis to explain it: to avoid spoilers I will say only that for reasons explained later in the game, people and creatures throughout the game world feel an unnatural sexual attraction to Celica specifically, simply because of who she is.
I think that the plot, though clearly contrived, easily fits within my suspension of disbelief as the world building seems to have been diligent enough to consider these things.