...people celebrate peace on Earth and good will toward men? This might come as a surprise to you but even we rational godless among you still apply christ-like attributes in our lives, like charity, kindness, and 'the golden rule.' Christians do not have a monopoly on these things. In our atheist home we celebrate Christmas for what it is: tradition.
Coincidentally, do you reckon witches get annoyed when Christian children celebrate Halloween? I guess they just do it because of...tradition.