why doesn't jehovah witness celebrate christmas

Jehovah's Witnesses do not celebrate Christmas because they believe it to be a pagan holiday. They believe that Christmas has pagan origins, and that it has been commercialized and corrupted over time. They believe that it is important to focus on the true meaning of the holiday, which is Jesus Christ's birth. Instead, they celebrate the Memorial of Christ's Death, which is a yearly observance held on the evening of Nisan 14.