The Pipers explain why they don't focus on Santa:
First, fairy tales are fun and we enjoy them, but we don’t ask our children to believe them.
Second, celebrating with a mixture of Santa and manger will postpone a child’s clear understanding of what the real truth is. It’s very difficult for a young child to pick through a marble cake of part-truth and part-imagination to find the crumbs of reality.
Third, we think about how confusing it must be to a straight-thinking, uncritically-minded preschooler because Santa is so much like what we’re trying all year to teach our children about God. Santa is omniscient, omnipresent, gives good gifts, but he also rewards you if you're good.
Kids still love Christmas, even without Santa; read more about the Pipers' experience here.