I think I've finally put my finger on what irritates me so much about the "put the Christ back in Christmas!" crowd.
It's not just that they're hectoring and self-righteous. That is annoying -- very annoying -- but not unusually so. Political partisans can be just as bad, as can academics. Just today I read about a Toronto cop who went onto Twitter to condemn people who tweet the location of RIDE checkpoints. That guy's hectoring and self-righteous, thus annoying. But not quite as bad, somehow.
It's also not just that they're deeply ignorant. That's actually sort of funny. I mean, Christmas trees are pagan; December 25th is a pagan holiday; exchanging gifts is a pagan tradition; misletoe is pagan; snowmen are pagan; Santa is pagan. Just about everything associated in the popular mind with Christmas is pagan. So watching (certain) Christians squawk about their traditions being maligned is good old-fashioned entertainment.
No, I think what bothers me the most is the inability to recognize a pretty important distinction, between what we could call religious Christianity and what we could call cultural Christianity. That is, I think there's an assumption underneath "put the Christ back in Christmas!" that everyone who celebrates Christmas must have a religious commitment to Christianity. Otherwise, no Christmas for you!
If you've grown up in the West, you've been steeped in Christian traditions. It's unavoidable. If you've grown up in a relatively multicultural city, you may know about other traditions. In my case, I went to school with a lot of Jewish kids, so could probably even today name most of the high holidays. I also went to school with a lot of Chinese kids, who used to regularly complain about going to "Chinese school" on the weekends. But we all knew about Easter and Christmas, as well as the Biblical high notes -- Mary & Joseph, wise men, crucifixon, resurrection, etc.
None of that implies any religious commitment whatsoever. It's pretty much just background noise: part of the set of cultural bases that we all absorb through exposure to a particular social group. Frankly, the idea that this amounts to any sort of religious faith is insulting to religion.
What it does imply is a set of expected behaviours at certain points in the calendar year. Come December, we're supposed to put up wreaths and decorate trees and buy presents. Come April, we're supposed to buy hot cross buns (shut up; I'm English) and chocolate bunnies. But this is all sociocultural; it doesn't even imply anything moral -- despite regularly irritating attempts to shame us all into generosity at Christmastime -- let alone anything as robust and life-shaping as a religious commitment.
So, what the "keep the Christ in Christmas" crowd are trying to do, in effect, is limit Christmas to just their own special group. Which means excluding those of us who grew up in a Christian context and absorbed the superficial behaviours without really trying. To my eye, this is not only arbitrary, but also rather unfair. It's a bit much to require kids to go along with Christmas celebrations, and then require the religious commitment. If the commitment matters, it should be put in place as an entrance requirement.
If Christians -- and I suspect it's only a subset of Christians, not near the majority -- really want to reclaim Christmas as their own special religious celebration, I'm afraid they're going to have to rename it. 'Cause Christmas to me, at least, is a cultural marker, and not really religious at all.