I understand this as pertains to quality narrative structure, but I don't think that's the way the vast majority of people are parsing this meme. I think almost everyone is thinking "man I really wanna fuck that girl who's 85% problems by volume" and I was just criticizing that preference I see in people.
As you say, it's fun to read a story about, I just see this occur as a real romantic preference in many people and I've basically never seen it end up well, so I was just gesturing towards the idea that, at some point, maybe you'd figure they'd learn not to put their hand on the stove.
Having long been in this camp of 'crazy girls fuck good is just cope for not even knowing what a healthy and loving relationship looks like', and also being driven back to fan writing by this trend, I think my .02 might help make a whole bill here.
'Smoothing out the edges' was a good way to put it, but I feel like it fits better for strictly adult relationships, when both personalities are mostly set in stone and the exchange of a relationship becomes a touch-up on what is more or less already there. One of the ways that HP works very well compared to it's world building or the mechanics of it's politics or magic is how it handles coming-of-age, and the process by which children both discover and decide who they want to become. In that regard, it's less of a 'I can fix this disgustingly broken Cluster B chick and get the memetic grippy-sock-pussy along the way' and more of a 'meeting you gave me perspective on things I would have never been able to cope with otherwise, and that protected me from ever becoming a fundamentally broken person in the first place'.
We are all having a lot of fun with the whole chud humor side of things where Malfoid is the smug racist noticer, but what really makes this appealing to me on a genuine romantic level is the posibilities offered by that exchange of perspectives, how it could change the context of formative experiences, and how that could change the outcome of entire character arcs. For Harry, that could mean learning from a Malfoid how to be more focused on an abstract purpose, how damaging it can be to take half-measures when the stakes are high, and a less naive sense of groups, individuals, and their real motivations. For a Malfoid, it could mean learning a more concrete sense that right is right and wrong is wrong, that most people can hold some worth and moral good in them despite all signs to the contrary, and that it's never too late to decide that you don't like a certain version of yourself, even if becoming that person seems inevitable. It isn't anything as simple as 'Harry teaches Malfoid empathy' or 'Malfoid makes Harry a chud', but more like showing how how two disparate but complementary perspectives can temper each other into new versions of the same basic people, that are now healthier and happier in regards to the world they live in.
Idk give me the puzzle pieces but it has a unique and unexpected appeal to the tortured and abused romantic in me.