The Watchtower endlessly prates on about pagan traditions in popular holidays - while the Bible itself is loaded with subtle pagan religious ideas - such as wicked spirits being cast "into Tartarus" (a pagan Greek place in which the rebels against Zeus got imprisoned) or "sacred secret" - a term the Apostle Paul likes that was adopted from pagan 'mystery' religions.
Then we can throw in the reference to being Divinely 'called Christians' in Acts - which uses a pagan term that refers to demonic Oracles of the day.
Of course, the Watchtower has no objection to accumulating millions of pieces of paper that feature occult symbols (any dollar bill!)
In recent years, for good measure, they have added birthdays and Thanksgiving to the official banned list, despite the sketchiest justification for doing so. If birthdays are wrong simply because they figure in two negative accounts, then it makes much more sense to ban dogs as pets because of all the negativity in the Bible about them!
The Awake is willing to 'look the other way' as to worldly celebrations when it comes to Latinas celebrating their 15th birthday. More converts, more money, and it's only once, right?
What is the real reason for all this zeal against celebrating holidays? It is this: to break up extended family relationships and maintain those broken family ties, as a means of continuing the 'cult' securely.
What is usually the biggest obstacle to a person "coming into the truth"? Very often, it is celebrating holidays, especially Christmas. People quickly understand that they must give up their extended family ties, as a practical matter. In a busy life, these holidays are often the only practical opportunity to visit and eat with relatives - and that is what the Watchtower wants to cut off.