Gee, I don’t know what movie others saw, but in TFA I saw a lonely girl clinging to the slim hope her parents were coming back, eeeking out a meager existence as a junk scavenger that was getting worse by the day if not week. The movie gave enough evidence there were few if any people she could trust. Whatever relationship she had with Unkar Plutt clearly had turned sour. It took interacting with BB, and Finn, and later Han, to realize she was waiting in vain. She wasn’t being naive, she was whistling in the dark.
https://www.collinsdictionary.com/us/dictionary/english/whistling-in-the-dark
Jakku makes Tatooine look like Disneyland. 😉
Given what little we find out about her past, her behaviour is more befitting a ten year old girl, than a twenty year old with her intelligence, and skill level. I don’t think her age, and demeanor are consistent with what we know about her past. She’s not being held against her will, she is self-reliant to the point, that she essentially could leave at any time to find out more about her parents, and make a better future for herself. She held the key to her own prison, and the main reason she stayed is essentially, because the writers needed her to stay put until the events of the film. The information given was perfectly fine as a setup, but her character needed fleshing out in subsequent installments. A lot of viewers in my view logically expected further development of her past, but sadly that thusfar hasn’t happened. I’m happy JJ confirmed we will be finding out more about that in TROS. It is long overdue.