If I could have more than one vote per post, you would have many for this my friend!
It is the celebration of the mas (birth) of Christ (Yeshua) - PC botherers are surplus to requirements. I acknowledge, as you do, the rites and traditions of many faiths. The fact that Jesus (Yeshua) was probably born in September is purely inconvenience so they celebrated it at the Winter Solstice to coincide with all the other festivals so that traffic would be awful and hotel rooms as rare as hen's teeth.
As they say, no room at the Inn, sling your hook!