But see, it is not like that.
People say "god bless you" to me or "have a blessed day" sometimes. I am fine with that. That makes me feel happy, because they are saying a nice thing to me. I celebrate the major holidays and if someone who celebrates a minority religion says something to me (although, why would they, I am a white dude) about their religion I can take it in stride. If someone wishes me Eid Mubarak, it is EXTREMELY CLEAR that they aren't just assuming I'm Muslim-- they know I am almost certainly not, but they are being friendly. What we're talking about is a culture where it is assumed that everyone is a Christian, and if you try to be nice and leave some ambiguous wiggle room for other religions you are called an asshole.
What we're talking about is my Jewish roommate who, everywhere he goes for almost 2 months out of every year, has to hear Christmas music, and has people saying Merry Christmas to him, and Christmas decorations everywhere, and if someone tries to be inclusive and says Happy Holidays everyone BLOWS A fuck*ng GASKET.
The store where I work has been blanketed in Christmas decorations since Halloween. Loud, horrible Christmas music. I just don't get it. I love Christmas and celebrate it, and even I do not want to hear that shit all the time.