Ah! What do Dark Jedi Strive for... Power. If there were no Jedi and someone was able to use the force and turned evil from it, more than likely he will strive to become more powerful because he can use his abnormal powers to his advantage. Then it is also most likely he will try to create an ideal for people to follow. It doesn't have to be the "Sith and their ways" but a group of bad people is more than able to develope.