Pedestrians and sidewalks

Why do some joggers find it necessary to jog on the road when there is perfectly good sidewalk to use? I know that I will get some flack for this one, but really people. Would you rather get hit by a car than use the sidewalk? I totally get that you have to run on the road when there is no sidewalk, but when there is one, use it. It really bothers me that I have to look out for you when there is a specific area (ie sidewalk) for you to use. What gets me even more is when you decide to not only run on the street, but run "in" the street. Can't you at least stick close to the side of the road and not be in the middle of the lane? My advice is if there is a sidewalk use it.