Most countries that "do" Christmas shut down on Christmas because the employees of places want to have Christmas, too. For example, Germany + Austria will be very, very quiet on the 25th/26th too. I never used to realize the way places go silent on Christmas because if you're always doing Christmas at home with your family it doesn't really matter. It's only when you're a 'stranger' in a 'strange land' and you're out there taking in the atmosphere that it hits you.

I personally think it's therefore generally a better idea to travel maybe the last weekend before Christmas if you want to get the Christmas vibe of a city. The Christmas markets are there, the cities are decorated, the music and all that is everywhere - but stuff is actually open for business and you can do stuff in the cities.