For some of us noble souls, Christmas is precisely about commercialism and the principles behind it. What I love about Christmas has nothing to do with religion (in fact, the religious aspects are what I don't like), but involve the social and wholly secular aspects of the holiday. People coming together and celebrating friendship and appreciation is not a religious idea, and I appreciate and applaud LEGO for reinforcing those aspects of the holiday.
Commercialism is about voluntary trade for mutual profit, and I can't think of a better allegory of friendship than that. Trading gifts is a concrete representation of that idea, and I think it's beautiful.
So were LEGO to have a Christian themed calendar, I'd be slightly offended (as I am with Playmobil's nativity set). Christmas has grown beyond it's religious roots to become a fantastic secular holiday, and I love celebrating it. The LEGO Advent calendars are something I look forward to each year, and I don't want that diminished by dogma.
(Sing to "Up on the Rooftop": Down in the thread, click click click, here comes the mod with the modding stick!)