Well, it's that time of year again, the time when the "War on Christmas" people stream out of the woodwork. It gets more ridiculous every year. This year it's the Starbucks red cups that are devoid of snowflakes or evergreen boughs or whatever. Definitely persecution of Christians!
Then we have Donald Trump promising that if he becomes president, we will all be saying "Merry Christmas." Dude, do you have any knowledge whatsoever of how government works? Of the constitution? Of the limits on executive powers?
I've said many times that I don't assume that everyone I casually interact with is Christian, so when I'm at Meijer, for example, I'll say something like "Have a nice holiday" to the cashier. It would be rude and presumptuous of me to assume that she or he is a Christian. They might be Wiccan or Jewish or Muslim or whatever. On the other hand, if someone says "Merry Christmas" to me, I'll say it right back. I'm all for having a merry holiday around the winter solstice.
We celebrate Christmas at our house even though we're not Christians. Most of the Christian traditions are pagan in origin anyway, but I have happy memories from childhood as well that make me want to continue the traditions I grew up with. I know any number of Christmas carols by heart, and I play them on CDs and on the radio. I like having a Christmas tree and gathering with the family both for Christmas Eve (at my sister's) and Christmas morning (with my kids and grandkids). As agnostics/atheists, we still like the traditions of Christmas. I think, actually, that Christmas is becoming more and more secular, and I'm good with that (but I still like a lot of the religious songs).
Saying "Happy holidays" is not a War on Christmas. It's an effort to be inclusive. This seems to be the one thing that some--and I emphasize the "some"--Christians cannot tolerate.