Well, let's consider that everyone is in a different place on their walk with God. Some consider following Jesus to be a solemn, ritual-filled experience, while others consider it to be a freeing, joyous experience totally divorced from the burdens of the old covenant. As Christians, we are not to set aside the commandment to love our brothers and sisters so that we can judge where they are on that path.
Nowhere in scripture are we told to celebrate Christ's birth, so we are certainly not told HOW to celebrate it. I believe it would be much more authentic and in keeping with the teachings of Jesus to celebrate Him EVERY day rather than to make much of one or two days a year.