@ pianodwarf, I'm not sure that I agree, at least not entirely. Yes, it's christian privilege, but I think it's mostly knee-jerk more than anything else. Maybe my perspective isn't a good representation of the wider world (or the wider America), because most of my acquaintances are not "strong" believers, they're more of the habitual type. Few attend church with any regularity.
I think for a lot of people, it's like an internet meme. "Everyone" is saying it, so it must be true, or relevant, or whatever. And then there's the mistaken understanding about the purpose of using the term "Happy Holidays" to replace "Merry Christmas" - what I always read or hear is that it's supposed to avoid offending people who are not christian, as opposed to an effort to include those people in the well wishes.
Every time I saw that nonsense on FB last year, I very politely pointed out the difference between the two positions, and asked why it's an offense to extend holiday greetings to everyone in a way that makes no assumptions about anyone's beliefs, but instead simply wished them all well, regardless of what religious traditions they follow. Not a single person was an ass in response, and a few people even stated that they hadn't thought of it in those terms.
Now, I'm not kidding myself that I started some sort of revolution, but I really do think that for many, many people, it's just a convenient bandwagon to jump on board. When pushed to reflect just a little bit, they may reconsider, or at least stop saying something so stupid.
Or maybe I'm completely in the wrong about this and I just happen to be very lucky to not live where I'd be surrounded by the crazy.
And I still don't understand why anyone would be looking for jesus at Walmart.