Understanding the force in a human mindset is equivalent to understanding any omnipotent religious deity. Force picks no side, it has no reason to. Doesn't have to fight for power, strive for food and glory, or anything. As the Jedi say, the force has a will of it's own.
Humans look at thing in a human capacity. Pure n' simple.
I always seen it that light or dark side of the force are not evil and good of themselves merely the energy of life and death. have to much of one or the other and you get crushing extremes.
Death and destruction is easy so the jedi shun it because its hard to stop.
It doesn't make the darkside of the force evil it makes it a power people shouldn't wield. We are living things and controlling the forces of death corrupt us.
Kriea's issue wasn't so much the force as much as the force moving force wielders to fight each other. light must fight dark to maintain balance and this was tearing the universe apart.
She wrong but right.