From the video below:
"With a few notable exceptions, good people are inherently good and evil people are inherently evil.
... history seems destined to repeat itself in this galaxy far, far away. There will always be a rebellion or republic fighting for freedom, and every crushed empire will be replaced by a new first order.
Narratives like this one work to reinforce the mythology that Good and Evil are clear & absolutes, that are in constant struggle. And in such a universe, lasting, systemic change is not possible.
The Force Awakens had opportunities to subvert, complicate or at least play with this Good versus Evil binary, but didn't seize on them."