Its kind of cool actually. I guess it depends on what your passion is. You could have a passion for helping people but it would still make you a sith.
I like this bit especially:
"The true meaning of the line "ůmy chains are broken" was a subject of argument among many Sith. The chains represented a being's restrictions; not just a Sith but any being in the universe. The restrictions could be those placed upon a being by someone else, or restrictions that one placed upon oneself. The ultimate goal of any Sith was to free himself from such restrictions, but not (as many failed Sith pupils believed) in the simplistic meaning of just being able to do whatever he wanted. The Sith desired to free themselves in order to reach perfection and fulfill their potential. They wanted perfect strength, perfect power, and perfect destiny, which, in turn, allowed one to do whatever they wanted for the most part. The person who had these abilities was known as the Sith'ari."