I must say I didn't have a problem with the way things played out then or now, although I could see how one might imagine that not all teen pairings lead to life-time marriages (even if that was the pattern that JK set with Harry's parents).
Lots of folks hate Ginny, and the movies mostly did not treat her well. But she actually did have a heap of personality in the book--more Fred and George's sister than Ron's, as she possessed a mischievous streak that Harry damn well needed after the traumas he experienced. Plus she was good on a broom and with a wand, so Harry met someone who shared his interests. I really liked the way that story played out in the books. It was inevitable, of course, given Harry's ties to the Weasleys.
Harry and Luna? Harry needed humor but that much whimsy? Perhaps not. Neville and Luna make far more sense.
How about Ron and Hermione? Again, someone a bit less serious with someone too serious. Seems right to me (perhaps, I, like JK, am projecting). Given all the stresses and adventures these folks faced together, it is not really that surprising that they end up together.
Plus the Weasleys desperately need to marry Muggle-born or half-Muggles, given that their family is very much pure-blood. Have to stop the inbreeding now.
This looks right to me:
|Appropriately from "Why Ginny W is Hated"|