The pressure isn't from Christmas or even from marketers. All cultures and religions have a mid-winter holiday. It is critical for all of us to celebrate life in the depths of Mother Earth's slumber. The crops are harvested and stored. The doors and windows are closed.
Travel is more difficult.
We become isolated from each other and sometimes from ourselves. Even in this modern technological world in which we live winter isolates us. So we create celebration. We find a reason to get out and mingle in the marketplace. We are forced to visit family and friends.