woodrrow
Registered
I think it is more readily used these days because of laziness.
Perhaps also adopted by store owners because it takes up less window space.
Also,some folks these days would get their azzes handed to them in a grade 3 spelling bee,so X is easier to write than that other thing
RSD.
The origin of it has nothing to do with laziness or window space. The symbol has been passed down through time, maybe without the true meaning behind it and forgotten. That is the path in which Xmas came from. The "X" in xmas still stands for the original meaning, whether or not people know it. Therefore, without the true meaning, the X would have never been substitued for "Christ" in Christmas. It's just another way of writing the word.
So, not only is the "X" more convenient, it's actually just as accurate as saying or typing/writing the word "Christmas"