Yes, they did not try to explain anything that would make a lifelong member of the First Order suddenly want to defect. A few, ad only a few--thankfully--have tried to fill in the Grand Canyon-sized gaps of the piss-poor script, but that's trying to deflect and erase the fact that Finn's every action and lack of identity proved he was meant to be a Black Buffoon stereotype from the beginning. He had no developed backstory, no cause of his own, and no recognition of who he was from what should have been his unique identity.
The FO's motives were a simplistic as the political implications and rhetoric of some the people behind the sequel trilogy; no detail, no believable reason behind anything.
In truth, we do see moral complexity in OT-Luke: specifically when he is constantly challenged to do things that his soul tells him is not right, such as his decision to temporarily suspend his training to rescue his friends when his moral leaders--Yoda and Kenobi--are telling him to sacrifice them for the greater cause. Later, Luke has moments of anger (goaded by Vader) throughout their duel, which nearly justifies the concerns of his mentors, but as Darth Vader attempts to get Luke to sell his soul to the dark side, Luke displayed a level of maturity well beyond his years by choosing death rather than sell his soul. Its that kind of religious/spiritual warfare between believable, compelling personalities--and which side had the stronger pull--that elevated the OT beyond the common sci-fi film and made it legendary (it certainly was not space battles). that has been lost ever since, with the ST being a hollowed out, "in name only" assemblage of SW trappings with no more substance than a video game.
Lucas seemed to forget that in his original intention / scripting / filming of Han shooting first, Solo was presented as ruthless, while his refusal to help the Rebellion (as he's loading his reward) continued to prove how self-centered he was, which made his sudden reappearance during the Death Star trench run the gasp-inducing surprise/payoff it was meant to be, pre-SE. It told the audience that he was a hero after all--something successfully built on in TESB as he--and Chewbacca--sacrificed time and again for friends and the greater conflict.
...and frankly, if some ancillary product (like a comic or novel) ever suggests he ran thanks to some bigger picture from/or the force, those publications can be tossed in the fire as ridiculous and as much an afterthought as JJA's blurting that force sensitivity notion in a recent interview.
All because Finn was never written to have a core, unique identity. His life was informed by Reay (first), then running and tripping for no apparent reason. The SW-PTB never cared to develop him at all, hence the very reason his "plots" (if you can call them that) in each ST film mean absolutely nothing to the main story. If you edited Finn out of the films, or gave his so-called part to another character, no one would miss him at all, or feel a vital part of the puzzle is missing.
His piece of a puzzle was not created for SW, but a terrible, racially explosive short subject from 1930.
...or just drape a pointless set of sequels in Star Wars trappings like a tawdry Disney park ride, lacking any sense of the grand myth and spiritualist heart that defined the OT at its best.
If only Finn's plotless plot was as coherent as you've presented it.
