Finn and Rey are two of the most lacking-in-subtlety audience surrogates I've ever seen.
The first time we meet Finn he's dazed and confused at what's happening around him.
He's everyone in the audience who hasn't ever seen a Star Wars movie, or who isn't invested in the universe.
He sees death and cruelty and reacts with horror and revulsion.
Just like the audience is supposed to.
He wants to escape what he sees as the evil forces surrounding him.
Like any sensible person would.
When confronted with big, explodey space battles and the rush of combat, he whoops and rejoices.
Just like the audience did.
He doesn't care about the politics or the history of what's going on, he wants to escape to somewhere far away and live an adventure.
It really couldn't be more spelled out.
He stays because of a connection to Rey, a wish to explore her world, to help her; he prances around with laser swords, wise cracks in Phasma's face 'cus he thinks that's what you're supposed to do in this universe. Eventually he's felled in defence of his friend(?) but survives to be revived by the life he was fleeing (the Resistance, the political situation, the conflict with the First Order etc.)
Rey is a loner, wistfully reminiscing about a time long ago when things were better.
You need this explained?
She spends her days gathering scrap and keeps hold of Star Wars memorabilia (rebel pilot's helmet).
Not at all subtle.
She's basically a good person, but hung up on something in her past that's holding her back. She has to go back to Jaku 'cus that's where she needs to be, waiting for the past to return.
No coincidence that it's Tatooine mk.2.
She's dragged into the larger conflict by outside forces, she's inherently knowledgeable about the universe and how it works, she's got skills that back this up and she flourishes despite not really enjoying herself.
Eventually she's forced into a confrontation where, and it cannot be shouted louder that it is, a FORCE AWAKENING makes her move on, face up to the world as it is rather than how she wants/dreams/hopes it to be and by the end has embraced the change.
As has been said, Abrams makes competent, uninspired, glossy movies, he doesn't do subtlety.
The reason you don't like Finn is because he's the new audience, enjoying Star Wars. He's the uninitiated holding on for the ride and not respecting the past 'cus he doesn't need to, acting the way he thinks he should based on what he's seen.
The reason you don't like Rey is because she's the fans, desperately clinging on to the past, unwilling to let go and the overwhelming message of the movie is to do just that and enjoy the new, like Finn does.
TLDR: Finn and Rey are audience surrogates and the way the movie depicts them is an unsubtle message to said audience.