Lucoa is one of at least seven responsible for the creation of Earth, Momi being another and the one that provides the explanation.
The intent was for the world to just have humans but in her boredom created creatures like herself, the mononoke, though eventually set things so they'd gradually become human over time to undo that "mistake" that irritated some of the others. Whatever god or gods have an issue with nonhumans are likely the ones the dragons in turn have a problem with. Honestly it's entirely possible Lucoa's in the same boat with the creation of dragons, essentially she'd be the dragon before dragons were even really a thing, though nothing outright says as much at this point besides the precedent for possibility.
That she's one of this group of gods adds to her standing by honestly, because she risks not only screwing with the balance between dragons but potentially dragging other gods in if she messes with their creations in the process.