Because those people like to whine about their fake persecution complexes, while they go around treating those who celebrate other holidays like dirt, ignoring the fact that they got 99% of the "good stuff" of the holiday from pre-Christian Pagan religions! LOL
Just giving a festival a new name and changing the meanings does not make it theirs. If they believe that, why don't we all go to their houses, change the names of their cars and drive off with them? LOL Same principle. Thus I'm under no obligation to call a decorated tree a Christmas tree if I'm not Christian. The tradition didn't come from Christianity and they don't "own" it.
They want everyone to acknowledge their day and their religion, and if not they cry "persecution." It's BS. There is no "War on Christmas." They're the ones harassing other people, no one is doing anything to them unless in retaliation.
I could care less what they celebrate and when, and I'm not going to whine that "they stole our holiday," even though it's clear that they did. What I will do is correct their ignorance of history whenever they treat a non-Christian like crap when they're supposed to be celebrating "peace on Earth" and "goodwill towards men."