No, *some* lightsiders do that, and those are usually the strong ones. A great many stick to the academies, temples, and other places where they can fill a peaceful role without ever ending up in the line of fire. For the Sith, even a researcher is going to have killed a few peers by the time they're well established.
But even if you disagree, the dark side force-users lead much *more* dangerous/violent lives than their light side counterparts.
But thing is why go through all that trouble/danger that comes with Dark Side when you can stay Light Side and get equal power? Just trim a few years from training?