Wrong. The only relevance they have is as a hook for fans and the media to hang their opinions on the performance of the team and to express any praise or discontent. Do you think if managers were "honest" there would be no discontent with the comments? Course not. What if giving an honest account of performance is not constructive? Or the manager doesn't see it the same way you've "honestly" seen it? He'd still be slagged off.
Just my own purpose when I traveled to chesterfield to watch a very below par performence Id rather just listen to a true reflection of the game like today he has dressed it up when posters who have been said we were very poor again.