Here in Spain (can't speak for other catholic places) there is a huge tradition in Christmas to place in public buildings (not only in churches) a Nativity scene. This year our district place a incredible big Goyesque stile one, brutal!
At home, even if you are not Christian, usually people place one, tradition over believin. I was born in not in the most catholic house by far (and by far I mean, we did not believe in God and less in the catholic institution) and we never, ever, miss to place our nativity scene.
Mine is with the miniatures that we use at my parents home, my mother made his owns years ago and I take the old ones for me, also my kids do some space cactus, so we integrated on the scene of this year.
Fun fact: in Spain lot of wargames people say "nativity, the warhammer of grandmas"