There are 2 major U.S. holidays within about a week of each other. Sometimes, to give people the season's greetings, people will say "Happy Holidays" (there are actually 4 major holidays, because both are celebrated the night before as well, in Eve celebrations, but two big events are expected). This is, I guess, something some people care about and are offended by.
Presumably, the source of this would be being admonished for saying "Merry Christmas" – but I've never seen or heard of that happening. There are also deeply weird undertones of not wanting anything except Christmas in the public square – not just excluding Hanukkah but also winter-themed decorations, in seeming defiance of nature. That writer also says that avoidance of assumptions is somehow offensive – I'm having a hard time squaring that with what I was told about assumptions as a kid. It also seems a bit odd – as much as he claims (couldn't be bothered to check gender, but the author, Heather Long, is confirmed to want people making more assumptions, so I'll assume Heather is a 'he') to be willing to have people wish them a Happy Hanukkah, he mocks people who suggest menorahs be added to an office Christmas scene.
This self-appointed Christmas defense league is bizarre and fraught with strange claims – for instance: that people won't buy clothes from stores without prominent Christmas-specific signage, because faith is so important to them. I'm beginning to suspect they're being disingenuous. I had to read someone non-humorously claim that the birth of Jesus is "surely one of the most appealing events for children in the whole spectrum of world religion" – not, ya know, getting a game console or eating candy or literally anything instead of historical childbirth reenactments. This is a level of borderline-insane delusion I'm not usually faced with, so I've decided to fill in some of the gaps here.
My honest best guess as to their feelings are: Christianity is great, Christmas is great. Culture is the stuff we do together, and making it abstract removes a common American-ness of celebrating Christmas – by far the least offensive thing for us to share together. If being American means anything, it probably ought to mean sharing the perfectly warm-hearted holidays we're all getting off work anyway because they're recognized by the federal government.
That's pretty reasonable, but I hope you can trust me when I say, it's far more carefully thought out than any of these inane op-eds I've been reading.
Weirdly, one of the most profound insights from all this can be pulled from one of the more incoherent editorials. Fundamentally, America (and Canada) are built on the idea of multiculturalism. But there was a blip in American history, a confluence of the Jim Crow south and the lead up to the Cold War and it's secular horrors, where America almost-successfully hallucinated it was just one thing (white Christians). Of course, that's complete nonsense, and previously they would have said the Catholic Poles had almost nothing in common with Irish Catholics, and Protestants wouldn't even identify themselves as having the same religion. But by choosing certain enemies, a lot of people presumed a uniformity that America never really had. This was not just mistaken, but a betrayal of core American values. America is the place anyone can go. We don't have to agree with our neighbors. We shouldn't! But we can be kind to them, wish that we knew the season's greetings that would delight them. Noticing our differences doesn't push people away. It pulls them closer, saying, I don't have to be the same religion or ethnicity as my neighbor – we're neighbors, that's enough. And I wish them the best season's greetings they can imagine, and happy holidays for however they wish to celebrate them.