Why Don't Churches Celebrate Christmas?

I'm always struck on Christian social media how so much time is devoted to celebrating Advent but not Christmas. There's so much writing and reflection about Advent leading up to Christmas and then, after December 25th, nary a peep.

After Christmas day, the trees come down at home and off church stages. Most churches didn't sing Christmas carols yesterday or have a Christmas-themed sermon, even though December 29 is smack in the middle of the Christmas season. And so is next Sunday, as a matter of fact, January 5th. Seriously, how many churches will be singing Christmas carols on January 5th?

I find it all quite puzzling, this strange half-effort to recover the liturgical calendar. Push, push, push to celebrate Advent, followed by a complete failure and lack of interest in celebrating Christmastide, the full Twelve Days of the Christmas season (or the eight days of the octave if you're a Catholic).

(Yes, I know that properly liturgical churches celebrate the full Christmas season. The churches I'm talking about in this post are those that work hard to acknowledge and celebrate the liturgical calendar, like with Advent, but who then fail in odd and confusing ways, like celebrating Advent and ignoring Christmas.)

I try not to be too much of a a grump about all this, but I do find it strange how so many churches work so hard and intentionally to celebrate Advent only to totally give up on Christmas. Seems strange to ignore the entire point of the season.