I meant it more in relation to hunting in general. Dad hunts for vengeance. The Demon has becomes his white whale. It is the big holy grail and I agree, Dad plans on going down with it. In fact I think he`d see that as merciful relief.
Sam too hunts out of vengeance and the more he finds out he is targeted, the more he realizes he HAS to destroy the Demon or normal life is out of the question. Unless he fancies more people going flambé. But after the deed is done, he wants to go back to school etc.

Dean otoh has stated often enough he is in it to help people. And while the Demon is personal for him, he plans on keep up hunting because there are other monsters. He has the natural Help-people-mentality. He chooses a life you don`t get much personal gain from but he`d do it anyway. And it is very high risk, as the rawhead incident showed each hunt is dangerous on its own. Also I`m guessing if he couldn`t hunt anymore he`d still prefer a "helper" job, fireman for example.

Now his family is his overriding concern and of course their saftey means more to him than getting the Demon. He doesn`t have the same burning need that John and Sam have, that makes it different for him. If say, a supernatural being killed Sam, I`d say batten down the hatches, there comes hurricane Dean. :)
But he isn`t as concerned about his own safety than he is about them. He is the Protector, especially to Sam (and Dad when he is around) but to the helpless in general.
Sam is willing and has proven to be able to walk away from that. For Dean it would take a whole of a lot to make that believable.