This blog post by YCombinator founder Paul Graham on writing versus speaking is worth reading start to finish.
What he says is probably inspired by the many conference speakers he saw. A big brand gets up the stage, unprepared, slightly rambling, but charismatic and full of catchy sound bites. In the end, when you look back, she actually did not say that much. Writing a good story is much harder.
This is what I encounter in presentation design every day. It is hard to design that story, but when you crack it, it often can be said in very little words but full of real content and insight.
But then again, I think that conference audiences are not always looking for that piece of insight or intellectual stimulation. Maybe they just want to laugh and have a good time.