1) Harry and Hermione are always there for each other. Now, I know all that stuff about Ron wanting to come back the minute he walked out on them and schist but really? Exchange Ron with Harry in this scenario. Do you think Harry would ever have walked out in the first place?

2) Hermione has (almost) all the answers and Harry is sick of being treated like he does. He would actually like to take a backseat and let Hermione commandeer the spotlight.

3) They have good chemistry. Now, shhh, all you Romione fans for a minute. But seriously. Remember that scene when Harry asks Hermione about what she did at the match? Did you not just feel the Harmony in the air? And when she comes down all dressed up for the ball? Remember that part?
Really, Ron and Hermione could've worked out with the whole "best friends but not dating" thing as well. And they would be cuter as the protective, bickering siblings.

4) They listen to each other. Harry is a good listener, and so is Hermione; when the need arises, they can both be there for each other. Ron has no clue what is going on with Hermione most of the time. He gets her perfume; Harry gets her a book. Harry can read in between the lines with someone like Hermione much better than Ron. And come on, man! Ron makes out with Lavender where Hermione can see them, whereas Harry follows her after she gets upset, finds her and tries to comfort her. This can also go for point 1.

5) They can stand up to each other without being abusive. Yes, this is true. Harry and Hermione do get mad at each other. Hermione exasperatedly tells him she's not an owl in GoF. Sometimes, she tries to help but has the wrong thing to say. Harry yells at her in OotP (that wasn't right but it was better than most of the things Ron does...) Neither Harry or Hermione are completely cool, grounded and sensible people; but they can get upset without doing things like purposely making each other jealous, setting birds on each other (Hermione), ignoring each other for stupid reasons they don't even tell the other person (Ron), or making cruel fun of each other.

Like, I get your point. Ron does cute things. He does love Hermione fiercely and does brave things for her and makes her laugh but love and managing relationships are two different things. I honestly do not think Ron and Hermione could have had a healthy and lasting relationship together. Now with Harry and Hermione, you have great potential for both.