This is interesting.
I much, much prefer the idea of the 12 days of Christmas and Christmas Day being the start of the festivities. Im not religious though so have never really been around people who view it this way, does it tend to be quite devout Christians who do it this way?
I have young kids so unfortunately we get dragged into a lot of festivities all through December, putting us more in the second camp.
But either way, taking the tree down on Christmas Day is absurd and very much indicates that you put it up far too soon.