She is so, so wrong. Harry + Hermione would have been so miserable to read. They're both such serious characters. Reading about them in a relationship would have been difficult and irritating and the opposite of fun. (And they never had any chemistry at all, good or ill. They were a believable, enjoyable friendship.) Hermione and Ron -- would they have irritated each other a great deal as real-life romances go? Yeah, sure. But they were so much fun to read.
(Also, as a woman with a Ph.D. who married a man without a college degree, f*** the narrative where the traditionally-successful woman is expected to marry the more traditionally-successful man. Why NOT marry someone who is good and kind and cares about you and makes you laugh and supports and is proud for your successes? In that sense, Hermione and Ron together is quite a progressive pairing.)
There's another home somewhere,
There's another glimpse of sky...
There's another way to lean
into the wind, unafraid.
There's another life out there...
~~Mary Chapin Carpenter