People are aware of the spacebar functionality in dialogues. If they don't press spacebar, then that's because they simply don't want to, and not because they are lazy/unaware/in need of guidance etc.
There is a StoryMode. If you want to see the story then play SM. An even if i have seen everything a thausand times i have the patience to wait. But if there is someone playing a HM FP and wants to see everything then i feel free to anoy him with different ways to mention that there is a spacebar to push. =)