As promising as Rey starting out as a scavenger literally foraging for junk to trade for food, which is what made me empathize with her and like her as a character, she didn't get much development after that.
I defending episode 7 and her Force abilities because they set it up that she almost unaware that she was even using the Force at all. I was banking on them answering just how it was that she was so good at everything in episode 8. Even Luke who was the son of one of the most powerful Force wielders in the galaxy had to be trained in the Jedi ways. Sure he may have had a knack for it but he still had to be taught specifically by Ben and Yoda.
Luke didn't train Rey in episode 8 at all. He told her his disillusioned thoughts but she never learned anything. Plus while Rey being a nobody is fine as a concept, I think just the idea that she is some naturally gifted Force adept and without training of any kind mind you, is able to do the things she does is not interesting at all. I get now why people were referring to her as a Mary Sue. Luke had to learn and even failed sometimes at using his abilities, thus making us grow and understand the character better as an audience because we witnessed him struggle with his impatience. Plus his anger at Vader in ESB and in ROTJ was his character flaw which he ultimately overcame. In this way we see the positive and negative outcomes of the same flaw by having the hero overcome it and the villain undone by it. That makes for powerful storytelling.
Having Rey not know who she is and not know her place in the galaxy isn't compelling enough of an arc without some sort of internal conflict that can be illustrated clearly on screen. It's part of what makes real life so frustrating when you can't articulate into words why you may be struggling with your identity, so how is it interesting when you have a character who is going through the same thing but has absolutely no doubts, fears, hopes, for this incredible power she is able to tap into? She doesn't seem to be tempted to tap into the darkness so there is no conflict there. She may be aware of it, but she's not tempted to use it so it's not the same thing. If the stakes aren't raised on a personal level and we aren't worried that she might not live or be able to save the day then how can we root for her? Plus Yoda tells Luke that she already knows everything she needs to know so there honestly isn't anything Luke or the Jedi Books can really teach her. So there is no conflict there either because there is no teaching that may result in her struggle to learn about her powers. She already knows everything.
She has no connection to any of the characters that are involved in this galactic conflict and she has no reason to stay, in fact all she wants to do is go back to Jakku and wait for her family. She has no reason at all to even be involved with the Resistance other than the script dictates that she needs to be there because she is the lead character. She could have easily delivered BB-8 to the Resistance and left for home. While I know that one could argue that the Force was awakened in her, then how or why doesn't that seem to answer the question of why her? Without SOME answers we as an audience struggle to care about her and what is happening on screen.
So if she doesn't know who she is, she doesn't have any interesting family history, she doesn't seem to have any weakness, she can pilot any ship she needs to, she can speak multiple languages, she can defend herself against more than one opponent, and she is able to use the Force without any effort or temptation to use it for evil, then HOW is she compelling as a character? Surely they could have used any of those pieces to give her some sort of interesting conflict that she could overcome?
The more I really start thinking about The Force Awakens the more it falls apart because it's just thinly drawn and really isn't adding anything to the story. In fact it's weakening the saga as a whole because it killed off or changed Han, Luke and Leia in order to strong arm audiences into liking characters that were not worthy to succeed them in the saga. The Last Jedi was the lynchpin that if handled right, could have made up for Episode 7's flaws but only added more problems to the mix and left little to resolve for episode 9.
Now the idea of drawing the story out with episodes 10, 11, and 12 seems tiring to the point where I'm getting indifferent to it all. 4, 5 and 6 were able to tell the story of Luke and company without it being too much and had they dragged it out I see where it could have gotten cheap. The idea of drawing out Rey's story and given how weak she is as a character seems nigh impossible without doing her further damage, which is a shame because Daisy Ridley is super talented and I really was looking forward to falling in love with her character.
The heads of Disney, Kathleen Kennedy, J. J. Abrams, Lawrence Kasdan, and Rian Johnson didn't need to "kill the past" in order to save the future of Star Wars but the tone this whole thing is taking, it seems as though they are possibly sealing it's fate.