Mars One is planning a colony drop, not a suicide mission. Colonies have a history of failing, but they also have a history of succeeding.
If we're talking about a mission with no hope of surviving to go on speaking tours, or build the foundation for a society elsewhere, I can't really see any good reason for it.
On the other hand, throw a NERVA, Orion, or a (FSM help you!) NSWR at the problem, and suddenly it's a shorter trip than most jaunts to the space station. If Bussard was 1/10th right, deep space missions won't be suicide missions.