Why does parents deceive their children on Christmas saying that Santa Claus gave them?

Parents do you not know that you are deceiving your child(ren) on Christmas that Santa Claus or St. Nick climbed down the chimney and left them with gifts under your Christmas tree? I really don't understand why you spend all your hard earn money only to say that someone else gave them. But, you trained and raise your child(ren) not to lie? Does that seem logical? Why wait to spend all that money at this time of year by going broke, going into debt, when you can give to your child(ren) everyday of their lives and not having to lie about the fact that, who, Santa Claus gave them?