Here, in an excerpt from the British paper The Sunday Times, Rowling discusses her decision:
“I wrote the Hermione/Ron relationship as a form of wish fulfillment,” she says. “That’s how it was conceived, really. For reasons that have very little to do with literature and far more to do with me clinging to the plot as I first imagined it, Hermione ended up with Ron.”
As a writer, I get where she is coming from, I really do. Hermione and Ron were a part of her original vision. They were the two opposite personalities that complemented each other and created the legs of the tripod for Harry's journey. It makes sense. And you know what else? It still makes sense. These are fictional characters - if you are going to pluck them out of their wizarding world and onto a therapist's couch then we can see that there would probably be some power dynamic issues in the Ron-Hermione union.
But as it works in the story, Hermione and Ron were a slow burn romance budding in key developmental years. Hormones were raging as wildly as the dark lord and they were close to one another. They also both served a function for Harry and were united in this in a way that Harry could not understand because he was: HARRY POTTER. They held him up, they kept him going, they were his sidekicks and legs of the tripod and every other cliche we can throw at the threesome dynamic.
Some may think Hermione settled or married beneath her by marrying Ron. But I think it is a perfectly plausible fictional romance to wrap things up with a big bow. Now, Rowling is the writer. The only reason we're all even talking about this is because these characters were birthed from her creative mind. She mentions their relationship was a kind of "wish fulfillment" and I get that, sometimes you cling to an idea and push it through in your writing despite other suggestions or editors screaming that Freud would never have believed their relationship.
What I am more curious about is why Rowling thinks Harry and Hermione would have been the better couple. Why would the literature have pushed those two together if she hadn't pushed her vision? Does she mean that while she was writing she felt an internal pull to make that the outcome? If she denied an intuition in the midst of the magic of writing then I understand why she has come out to say what she has, but everything still works, J.K. Everything is down in print and perfect the way it is.
Now, my question is...why did they all end up together at all? Very few friend groups from youth maintain that kind of pairing. Was it the crisis of their existence together that kept them together? Or is it all just...the product of young adult fiction?