Question

I pose this question as it both makes me happy yet I don't understand. Why do non Christians celebrate Christmas? The point of Christmas is to embrace the gift that God gave us in Jesus and cherish the gift that Jesus gave us in his life to spare all of us from our sins. In remembrance of these gifts we give to others in symbolic tradition of the gifts that were given to us upon Christ's birth. I mean to an extent I understand why Muslim and Jews may take part as they both believed Jesus was at least a prophet and an important figure. I guess my real questions is why do Atheist and other non believers take part in a holiday that is contradictory to their beliefs.