My take:
Shouldn't Christians be encouraged to celebrate Christ's birth every day? Don't give the devil any day of the year. In fact we should celebrate everything about Christs life and accomplishments including creation, the incarnation, the virgin birth, his life and ministry, his atonement, his resurrection, his ascension and his promised parousia. All for us and for our salvation. These are the absolute greatest events in history.
And yet Jehovah’s Witnesses cannot praise him or even thank him for his grace and mercy and sacrifice on our behalf.
Pity