About 50 years ago, merchants started advertising products that they hoped would be chosen as gifts for a particular day of the year as those gifts that would produce a Merry Xmas. At that time, many Christians were appalled at the “X”. Merchants and others justified the elimination of Christ’s name from his birthday as using His name made the word too long for modern advertising. Of course others realized that this was a step in secularizing a religious holiday.
More recently saying Merry Christmas or Happy Chanukah are viewed as exclusionary salutations. The politically correct salutation for the December days of religious remembrance is Happy Holiday. I am by nature a conciliatory, inclusionary person. I am also a religious person. I still wish persons that I meet during December a Merry Christmas or a Happy Chanukah. Secularists can just suck it up.