Santa Clause, The Easter Bunny, and the Tooth Fairy are all handicapped bullstuff that shouldn't be lied about to kids in the first place.
Little children, seeing as the are little and don't fully understand anything outside of their age, don't truely understand holidays. So, what parents did is that they created fictional characters and planted it in their minds, creating a message that they can understand.
I mean, really... What do you think childeren will most likely understand?
1. A fat guy in a red suit giving out presents?
or
2. The birth of the christian messiah that came to save the jews from their sins?
Yes, its all bullstuff, but we don't want to blow out their minds now do we?