I can understand people not wanting to be part of Christmas, Easter, Valentine's, birthdays, your whole list @zbw565
I can also understand people doing all those things.
We do some, don't do others. Are you really so unenlightened you can't understand why some people enjoy it?
We are not religious, in the religion sense, but we enjoy this crazy ride called life, with these stardust bodies we inhabit that will eventually return to the cosmos. In the UK, not sure where you are based, because of the earth's tilt and orbit, in the water holding goldilocks zone, winter, deep winter brings very short days, long nights, we are almost at that peak (this weekend if you are unaware). Stonehenge was built to note the shortest day as well as the longest, it is thought it was more important to know the shortest day to began the plan for next year's crops. (I can do a whole blurb on the beginning of agriculture but I'll skip that).
Looking at the sky has led to continuous, and remains still, a source of pursuit to the very edge of human knowledge and understanding of that time, there is other life out there but it's a fuck of a long way away.
If you know the continuous traditions throughout the ages of many human celebrations (and it might not be Christmas but all lands have similar festivities not just the west) you can use one time in the year to connect to the human celebration of ritual, charity, gift giving in thanks of our wonderful existence. Christmas is ours. This one time of year where you can choose, again not compulsory, to be part of that link.
So again I don't understand your lack of reasoning how others can want to be part of this.
And posting on the Christmas board is goady, you know this, I assume when people do this they just want online attention because something is lacking elsewhere. I might be wrong.
Perhaps if you want people to agree with your point of view, not goady, you might fare better on the Chat Board.