Kalu,
You are so right.
The main issue with Christmas and other heavily involved family situations (weddings, new baby, birthdays, special holidays) are the expectations.
Whose "traditions" win? One person's or the family learns to compromise? The latter, while ideal, is not possible, as seen multiple times in this board
Items such as where son/daughter spend Xmas (on their own, with his parents, with her parents, etc), whom travels to whom, who is hosting, what is cooked for the meals, staying in hotel vs relative's home, etc., can become a battle.
If that's the case, what happens? Family conflict and resentment starts.
I personally started enjoying Xmas as soon as I was free from "family expectations" and had a call on how I spent my time.