Why Harry/Hermione doesn't work as well as people think
When talking about this discussion we must realize that J.K. never said explicitly that Harry should have married Hermione, but since fans of this hypothesis often take her words to this extent, my goal is to examine an aspect of this possibility that puts its' optimal status is jeopardy.
And in short words, the problem is this: while we can argue forever why Harry/Hermione should have happened over Ron/Hermione, or why not, if we come to the conclusion that it should, indeed, have happened, we are also implying that Harry/Hermione should have worked over Harry/Ginny, and that is another discussion entirely, and one that tips the odds away from Harry/Hermione. I'll explain what I mean.
These relationships, in my opinion, were based on broad connections we make in literature and film, between certain types of personalities. Ron/Hermione are a very simple case of opposites attract, but Harry/Ginny are not. Their relationship is one of two very independent people who are very much alike. While Ron and Hermione complement each other, Ron making Hermione more relaxed and Hermione being the person who comforts Ron when he's insecure or in distress, Harry and Ginny don't, and in fact, I don't think they would ever allow anyone else to change them. They need each other but, in some ways, they don't. To make a wild comparison, they are like Nathan and Elena in the Uncharted series. It's their independence that attracts one to the other. They see themselves in the other, the only one that understands the other because they are alike, but they never push themselves towards the other's side.
Now, how does this invalidates the possibility of Harry/Hermione being better? Well, it comes down to Harry himself, and what attracts him to Ginny. I'm not sure whether it was intentional on the part of Rowling or not, but when you examine the two girls Harry has a romantic relationship with, Cho and Ginny, you realize that Harry's feelings for both establish the difference between having a crush and falling in love. Cho is Harry's crush. She's someone that Harry idealizes in his head, but when they are together, he comes to realize that he's not a fan of her personality. True, she was in deep emotional pain in OotP, but by Harry's rejection of her behaviour, we can extrapolate exactly what Harry is not attracted to. And Ginny, besides playing Quidditch like Cho, is the total opposite of her, or to be fair, the total opposite of her state in OotP. Sure, her playing Quidditch plays a part in Harry's attraction, but in fact, as Ginny herself later explains, she started being her true self, on Hermione's advice, instead of her obsessed with Harry self, and it was only then when Harry started becoming attracted to her.
Now, to be fair, Cho is not like Hermione, but she's more like Hermione than she is like Ginny, and that is the basis of why I think Harry would eventually stop being attracted to Hermione. They are great friends, but in a relationship, I think that they would tire of one another. Just picture a Harry/Hermione dinner party. They would throw the worst dinner parties ever! They would be sooo boring!
Ron and Hermione would probably get in a lot of fights due to their conflicting personalities, but I don't think the flame of their chemistry would ever go away. Like Howard and Bernadette in the Big Bang Theory, or Chuck and Blair in Gossip Girl, they plain and simple, love each other. It doesn't make any sense, but they're in love, and that does not have to make sense to make sense (quoting How I Met Your Mother here). Harry and Ginny, on the other are the couple who love to have and live their own lives, but at the end of the day, they will get home and be glad the other one is there.
Now, this is my opinion, and you're free to have your own. Go ahead and leave your opinion on the comments below, and as always thank you for reading.