I understand that you feel that way, but regardless of the history I can assure you that my daughter reacted in the same way as many adult American Christians do: she understood that Christmas was a religious holiday (and that it wasn't hers). If a bunch of people believe that a holiday is a religious holiday, telling them about the cultural history behind the details of the celebration isn't actually responsive to that belief, any more than a focus on the true story of the Maccabees makes Hanukah solely a cultural holiday.