Rules-lawyering drama queen but not a munchkin
That problem wasn't with the film but with the fans. It works just fine in the film: she was counting down the time she was alone, she wanted to go back to Jakku, and she had a vision of being abandoned. That was her arc: learning to live with the fact she had been left on her own and they were never coming back. Which Maz Kanata says outright.
At no point does it imply her parents were anyone special.
That was all us. Again, the problem comes from the fans. Not the film. The fans.
The expectation that she was somebody was what people read into the movie. Largely because of the parental twist of Empire Strikes Back. People expected them to do the same thing again. Again.
Then the sequel came out and didn't cater to the wild theories everyone had been fan waking themselves raw over for a full two years and somehow that made it a bad film....
We set the expectations. It's not the responsibility of the film to pat us on the head, give us a lollipop, and reward us for wildly speculating.
It's not like the film would have been better if Rey had been a named character's child or grandchild. At best that just creates more questions and continuity problems.
The most interesting part of The Force Awakens wasn't the revelation of Kylo Ren's parentage. Because everyone had guessed beforehand. No one was surprised, as there were literally two options.
But again... THAT WAS A PROBLEM OF THE FORCE AWAKENS.
Because 90% of that movie was a giant rehash of A New Hope.
That's probably why I kind of like the Last Jedi, I went out of my way to arrive as a blank state to the movie theater. I avoided trailers, reviews, social networks and youtube channels. I had no pet theories, I just wanted to see how they were going to fix the mess left by the force awakens. Somehow they made everything worse, but the carnage was fun to watch. (Except for the casino scene, that thing went out forever. And I would have loved for Finn to have made that heroic sacrifice, it would have saved so many lives and completed his character arc... )