its seems like one hell of an assumption that the C172 pilot actually saw the dash 8 on the runway. So far no one commenting has said they would consider landing on an occupied runway. any reasonably student would make a go around in the given situation if the saw the hazard.
its interesting to see the first assumption is that the hazard was seen and ignored or deemed safe and not that the hazard went unseen.
There are plenty of examples of low light\night landings where a runway incursion has occurred and the landing pilots couldn't see the aircraft on the runway.