In the past I have been very vocal when hearing about Christmas being taken out of the Christmas holiday. Challenges to public displays, stores substituting holiday for Christmas, etc. have always made me angry. A podcast last year by my friend Jeremy Sarber started me looking at it and I've pretty much done a 180 on the issue.
The birth of Jesus wasn't observed in Europe until the fourth century and in the U.S. until the late 1800's because the date wasn't known and it wasn't deemed important. His death, burial, and resurrection (Easter) is the defining moment that separates Christianity from all other religions.
I hate to give credit to athiests and separation of church and state activists, but it is true that the pagan Winter Solstice celebration was appropriated by Christians trying to win people over to Christianity and leave behind the sinful partying that had become commonplace.
I still believe that the First Amendment to the Constitution only applies to Congress, the federal government. If a city, county, or even state wants Christmas displays on public property it is not the business of courts to force removal. But I'm choosing to look at the big picture and let it go. Render unto Caesar that which is Caesar's.
Businesses should always be free to choose to celebrate Christmas or not to celebrate. Its customers can decide for themselves if they want to patronize the business or go where they can have their beliefs validated. I will still celebrate Christmas with family and friends but will no longer make a loud, public protest when a company leaves Christmas out of its sale advertisements. Christmas is an artificial holiday and refusing to acknowledge it is not a blasphemous offense.