I think Hermione wasn't qualified to be in a relationship, but for different reason. Sharp-canary-beaks-to-the-face reasons.

I am relieved to hear that Ron/Hermione was a mistake, but not because I'd prefer either of them in a different ship - just because I'm against that specific ship.

(TBH, I think the more JKR expanded on any couple, the worse it got. Literally the only couple I really ship in-canon is Lucius/Narcissa. The rest is fanfic territory. She's NOT a romance writer.*)

*That is to say, not that "she isn't writing in the romance genre", but "she, personally, cannot write romance".