[yatros from flatwater]

Who cares? Yeshua (Jesus) strongly objected to the elevation of human traditions over the commandments of the God of Israel (Matt 15:6, quoting Isaiah 29:13). The substitution tradition goes way back to the fall in Eden. Is it something to celebrate?

As far as the origins of Christ's Mass, see the Catholic Encylopedia for a fairly comprehensive discussion of the various pagan contributions

[Adder]

"Is it something to celebrate?"

You bet it is. It represents a continuity of tradition that has lasted for hundreds and maybe thousands of years. It is "inclusive" in that it honors and respects "diverse" traditions by including them.
The fact that a Yule log is a Druid holdover does not diminish the holiday of Christmas, it enhances it.
Those who see some "evil" or nefarious purpose are being somewhat disingenuous.