Well, deep in conservative christian country where I was born and raised, to replace the name of Christ with an X was a bit short of blasphemy. I will offer that it may not be good justification for not reading the entire text, but my money is on; it is a clue to what follows.....
I thought that it was widely known by now that that is simply not true- that the X in X-Mas is, indeed, in reference to Christ. It is basically a symbol representative of the cross. This goes back many many years and has been reported in many myth debunking publications.