the sith as a whole are evil. the actions they promote and encourage are by no means good for anybody but themselves. if you want to use the jedi as a counterpoint, yes the jedi pull dick moves every now and again but more likely than not, it's to benefit a large group of people. you can also argue about "natural balance" and other nonsense but really, sentient beings are above the laws of nature. we have the ability to counter nature with critical thinking and reasoning. the mere fact that people keep arguing this point if proof that we are beyond (or should be) animals in the way we conduct ourselves.