It gives me insurance, against some of the situations you see posted on this board. I have been told by multiple pilots that they get these calls, when in fact they are completely with their wits and never received notification, and, or checked their sked per the PWA, only to be called and asked where they were. It is just good practice so that if I am ever confronted with a question as to why I did not report or why I did not acknowledge a rotation, I will have my proof.