It is the art of being really lazy and having no redeeming value as a person.
Dude, My roommate is getting straight A's in Schleptitude this year.
similar to ineptitude, only not a quality, but rather a temporary state brought on by an influx of schleps in a confined space, thereby bringing a state of schlepness to all non-schleps in said area. Will gradually decrease once removed from the schlepified area, provided no schleps choose to follow.
Man, if I don't get away from these schleps soon, I'm going to come down with some serious Schleptitude.