If they have to fake it, doesn't that tell that something is wrong with the rule in the first place? That is like having a speed limit on a stretch of road that is so low that the maximum safe speed on that road is 10 times the speed limit, and then having speed traps along that stretch and wondering why everyone is "speeding". If "everyone" is doing it, I would suspect that the whole rule is at fault.
Even if I don't believe that jesus is or was real, I will not judge everyone around for celebrating Christmas as they see fit. I myself enjoy Christmas songs even if they have the Nativity scene in it, since I know that the Nativity scene is really pointing to the real Christ--the sun. The same for the other holidays. I put up nice decorations for these events in my apartment hall, and see no problem with others doing the same. About the only common way to celebrate Christmas (and other holidays) I will judge anyone for is if they drink and drive, and then because they put everyone on the road in danger and because it is actually a crime to drink drive.
But no faking things. It is Christmas, and that means Christmas (even though the "Christ" is in fact the sun). None of this "winter" rubbish, or other means of watering things down. And it is the whole nine yards (the tenth is going to church, which I have about as much use for as for drink drivers--which is none). Christmas music (and not just "winter songs"--Christmas songs). The whole deal with the lights (LED lights which use much less energy and are much safer than incandescent or fluorescent lights). Decorations including Santa Claus (and crosses which represent, not jesus, but the chakras in your soul).
Ditto for Halloween. I decorate for that as well, and put out a large dish of Halloween candy (no razor blades--you need to get those separately, because I believe scum that put drugs and razor blades in candy deserve a nice long jail sentence). (And I believe that getting hit by cars is far more a danger than drugged or razor-bladed candy.) I put out that bowl of Halloween candy (which come directly from the store, still in their wrappers) the morning of Halloween and take it down the next morning. I don't see anything wrong with Halloween celebrations (again, the most common problem is careless driving, including drink driving--which is the one thing I give Bah! Humbug! to).