A real understanding of history appreciates that however myths and legends are clothed they represent universal truths. The fact that elves and reindeer are part of the legend at one time and not at another is irrelevant. St Nicholas has been part of human experience and mythology for 1800 years. The legend has evolved, is different for different times & cultures but it captures a human truth.
I think those universal shared stories, legends, myths are uniquely valuable and give testimony to the truth that humans have been the same clay throughout history, had dreams ambitions, lusts, aspired to goodness, fell to evil. It is the fabric of society woven over centuries and however you may protest, however some may commercialize it Father Christmas is part of the human story and the magic of Christmas is real except for those who turn their backs and deny its power. If you want to live in that sparse world it is your right but you cannot change the reality for others.
I'm approaching this from a strictly bibilical Christian perspective. And from that perspective God implores his people time after time to NOT follow after the myths and legends of the people who do NOT follow him.
Deu_6:14 You shall not go after other gods, the gods of the peoples who are all around you
Deu_12:30 take heed to yourself that you are not ensnared to follow them, after they are destroyed from before you, and that you do not inquire after their gods, saying, 'How did these nations serve their gods? I also will do likewise.'
1Ti 4:6 If you instruct the brethren in these things, you will be a good minister of Jesus Christ, nourished in the words of faith and of the good doctrine which you have carefully followed.
1Ti 4:7 But reject profane and old wives' fables, and exercise yourself toward godliness.
What you're talking about is nothing but re-packaged things that God told his people to reject long ago.