The secular culture has got it right: Christmas celebrations should end on Christmas day, not on Epiphany. The real Christmas season is what the church calls Advent. During that season, we recall the past, but with an eye to the future, to gathering with family and to commemorating a specific event in history, the birth of Jesus of Nazareth. When Christmas day finally arrives, Jesus' birth should be acknowledged and celebrated on that day. After that, we should — and the secular world does — get back to business.
The church annually insists on prolonging the Christmas celebration through Epiphany. That makes more of the occasion than it merits. What changed the world was not Jesus' birth, it was his ministry and its aftermath. (More generally: It's self-indulgent for the church to engage every year in extended liturgical celebrations of historical events, as though the past were more important than the present or the future.)
In my all-time favorite TV series, The West Wing, fictional President Josiah Bartlet would never allow his staff to wallow in their successes or their disappointments; his most characteristic line of dialogue was a question: What's next? With all the work that remains to be done in the world, the church could do worse than to keep that question in mind in its yearly liturgies.