Occasionally, someone wants to make an adventure that ISN'T wacky, crazy, or otherwise humorous, and decides to go down the dark path to making a SERIOUS adventure. Readers, however, usually disagree, and thus the author is be flooded with tons of suggestions that would, well, wreck the mood more than a little.
To counteract this, the author usually posts something that out-and-out proves that this adventure is not to be taken lightly. Killing off a beloved character, cutting off the hero's arm, taking a silly suggestion but then playing it brutally straight... anything like this can be used to whip the audience into the correct shape, and get them making the kind of suggestions the author wants. These are just the subtle ways of doing it, of course- occasionally the author just comes out and tells the audience to shut up himself.