Correct. Palpatine did a lot of evil things, like invade Naboo and start the clone wars, and the massacre of the Jedi, just to get to his goal, so his moral nature was definitely messed up. But that doesn't explain why the Sith themselves are evil., and why the rebels were justified in overthrowing the Galacitc Empire. If Anakin turned his back against Palpatine in episode 3, not turning away from the darkside, still being a dark-side force user, but helped the last remaining Jedi against the Emperor, they would still reject him and consider him to be an evil person, just because he was a Sith. Even if sith vader/anakin helped them out, he would still be evil, just because he was a Sith. When obi wan told padme that anakin turned to the darkside when he visited her house on Coruscant, the reaction and dialogue wasn't "Oh, Anakin became evil because he did terrible things against the Jedi and betrayed them". Padme and obi wan's reaction at first was "Oh, no, he now uses the darkside of the power and has evil superpowers". Which, according to the film, he was evil for just that. The Sith were evil because they had dark powers. Doesn't make sense to me.