"And what makes those 7 men different from other heads of organised religion? All organisations have a head who dictates terms to some degree."
Have you considered that there may be no difference between them and that they're all wrong?
You feel that birthdays are an Ego boost for people? Can you tell me what's wrong with giving an ego boost to people you love? Can you point me to a study that shows that birthdays are responsible for people becoming out of control ego-maniacs?
I like to make my wife and child feel appreciated on a day to day basis, but a birthday gives the chance to really focus on that person and make them feel valued and loved. It strengthens the family bonds and brings us all closer together. That happens to a lesser extent with non-family members too. Birthday's strengthen social bonds.
That exposes what the real purpose of the man-made rule banning birthdays is: Isolation of the individual through the weakening of social bonds.