You see, I do not observe the holiday, but it sure is important to most of my coworkers.
I have the exact same opinion about this holiday. I'm not a religious person and don't observe any religious holidays - the only holidays I actually care about, for sentimental reasons are Independence Day and New Years...
...And my birthday - well, it's not recognized as a holiday just yet but I'm working on it :-p
But I know how important this holiday (and Thanksgiving) is for many of my co-workers. My experiences with my first job at a Mennonite hospital in a smallish town in the middle-of-nowhere-midwest-America just solidified the whole thing.
So I always volunteer to cover someone else's shift for Christmas and Thanksgiving - even if it's not my turn.
The way I see it: I get paid time and a half and someone gets to stay home and spend that time with their family/loved ones.
It's a win-win solution as far as I'm concerned. :-)