"Also, I got older (and gayer), I found myself really rejecting the binary of good and evil that seemed to be so key to the Force mythology that we are taught. Even if we look at the dualism that it is based around, like the concept of Yin and Yang, it is not that these two forces are in conflict constantly, but that they are “complementary, interconnected, and interdependent in the natural world, and how they may give rise to each other as they interrelate to one another.” Basically you need both.

In the old Legends, there were also examples of Sith and Jedi working together. For example, Darth Vectivus, known as the Sith Lord who did no evil. He simply learned and had enough balance and self-control within himself to remained balance while being a Sith. That is interesting."

source: themarysue