Am I supposed to object to this?  Who are you supposed to blame other than the messenger?  The messenger may be carrying bad news or criminal orders, but how is one to determine where the message comes from?  It involves time and effort…  And an attention to detail.  You might never be able to determine where the message comes from, and then whom can you blame?  Blame yourself?  Out of the question.  Much better to blame the messenger because the messenger is right there, immediately at hand, available.  And because of his “lowly” station as a messenger, no one is likely to object.  It is a perfectly acceptable and compelling strategy. 

For some reason, messengers don't seem to like this analysis.